William M. Vollmer

Effects on Blood Pressure of Reduced Dietary Sodium and the Dietary Approaches to Stop Hypertension (DASH) Diet

Background The effect of dietary composition on blood pressure is a subject of public health importance. We studied the effect of different levels of dietary sodium, in conjunction with the Dietary Approaches to Stop Hypertension (DASH) diet, which is rich in vegetables, fruits, and low-fat dairy products, in persons with and in those without hypertension. Methods A total of 412 participants were randomly assigned to eat either a control diet typical of intake in the United States or the DASH diet. Within the assigned diet, participants ate foods with high, intermediate, and low levels of sodium for 30 consecutive days each, in random order. Results Reducing the sodium intake from the high to the intermediate level reduced the systolic blood pressure by 2.1 mm Hg (P<0.001) during the control diet and by 1.3 mm Hg (P=0.03) during the DASH diet. Reducing the sodium intake from the intermediate to the low level caused additional reductions of 4.6 mm Hg during the control diet (P<0.001) and 1.7 mm Hg during t...

International variation in the prevalence of COPD (The BOLD Study): a population-based prevalence study

BACKGROUND Chronic obstructive pulmonary disease (COPD) is a growing cause of morbidity and mortality worldwide, and accurate estimates of the prevalence of this disease are needed to anticipate the future burden of COPD, target key risk factors, and plan for providing COPD-related health services. We aimed to measure the prevalence of COPD and its risk factors and investigate variation across countries by age, sex, and smoking status. METHODS Participants from 12 sites (n=9425) completed postbronchodilator spirometry testing plus questionnaires about respiratory symptoms, health status, and exposure to COPD risk factors. COPD prevalence estimates based on the Global Initiative for Chronic Obstructive Lung Disease staging criteria were adjusted for the target population. Logistic regression was used to estimate adjusted odds ratios (ORs) for COPD associated with 10-year age increments and 10-pack-year (defined as the number of cigarettes smoked per day divided by 20 and multiplied by the number of years that the participant smoked) increments. Meta-analyses provided pooled estimates for these risk factors. FINDINGS The prevalence of stage II or higher COPD was 10.1% (SE 4.8) overall, 11.8% (7.9) for men, and 8.5% (5.8) for women. The ORs for 10-year age increments were much the same across sites and for women and men. The overall pooled estimate was 1.94 (95% CI 1.80-2.10) per 10-year increment. Site-specific pack-year ORs varied significantly in women (pooled OR=1.28, 95% CI 1.15-1.42, p=0.012), but not in men (1.16, 1.12-1.21, p=0.743). INTERPRETATION This worldwide study showed higher levels and more advanced staging of spirometrically confirmed COPD than have typically been reported. However, although age and smoking are strong contributors to COPD, they do not fully explain variations in disease prevalence-other factors also seem to be important. Although smoking cessation is becoming an increasingly urgent objective for an ageing worldwide population, a better understanding of other factors that contribute to COPD is crucial to assist local public-health officials in developing the best possible primary and secondary prevention policies for their regions.

Comparison of Strategies for Sustaining Weight Loss: The Weight Loss Maintenance Randomized Controlled Trial

CONTEXT Behavioral weight loss interventions achieve short-term success, but re-gain is common. OBJECTIVE To compare 2 weight loss maintenance interventions with a self-directed control group. DESIGN, SETTING, AND PARTICIPANTS Two-phase trial in which 1032 overweight or obese adults (38% African American, 63% women) with hypertension, dyslipidemia, or both who had lost at least 4 kg during a 6-month weight loss program (phase 1) were randomized to a weight-loss maintenance intervention (phase 2). Enrollment at 4 academic centers occurred August 2003-July 2004 and randomization, February-December 2004. Data collection was completed in June 2007. INTERVENTIONS After the phase 1 weight-loss program, participants were randomized to one of the following groups for 30 months: monthly personal contact, unlimited access to an interactive technology-based intervention, or self-directed control. Main Outcome Changes in weight from randomization. RESULTS Mean entry weight was 96.7 kg. During the initial 6-month program, mean weight loss was 8.5 kg. After randomization, weight regain occurred. Participants in the personal-contact group regained less weight (4.0 kg) than those in the self-directed group (5.5 kg; mean difference at 30 months, -1.5 kg; 95% confidence interval [CI], -2.4 to -0.6 kg; P = .001). At 30 months, weight regain did not differ between the interactive technology-based (5.2 kg) and self-directed groups (5.5 kg; mean difference -0.3 kg; 95% CI, -1.2 to 0.6 kg; P = .51); however, weight regain was lower in the interactive technology-based than in the self-directed group at 18 months (mean difference, -1.1 kg; 95% CI, -1.9 to -0.4 kg; P = .003) and at 24 months (mean difference, -0.9 kg; 95% CI, -1.7 to -0.02 kg; P = .04). At 30 months, the difference between the personal-contact and interactive technology-based group was -1.2 kg (95% CI -2.1 to -0.3; P = .008). Effects did not differ significantly by sex, race, age, and body mass index subgroups. Overall, 71% of study participants remained below entry weight. CONCLUSIONS The majority of individuals who successfully completed an initial behavioral weight loss program maintained a weight below their initial level. Monthly brief personal contact provided modest benefit in sustaining weight loss, whereas an interactive technology-based intervention provided early but transient benefit. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00054925.

Effects of comprehensive lifestyle modification on diet, weight, physical fitness, and blood pressure control: 18-month results of a randomized trial.

Context Can adults make sustained changes in unhealthy lifestyle behaviors? Content In this multicenter trial, 810 adult volunteers with prehypertension or stage 1 hypertension were randomly assigned to a multicomponent behavioral intervention group, a group combining the behavioral intervention plus the Dietary Approaches to Stop Hypertension (DASH) diet, or an advice only group. At 18 months, participants in both behavioral intervention groups had less hypertension, more weight loss, and better reduction in sodium and fat intake than those receiving advice only. The participants in the DASH diet group also increased their intake of fruits, vegetables, and fiber. Implications Motivated adults can sustain several lifestyle changes over 18 months, which might reduce their risk for cardiovascular disease. The Editors The public health burden of chronic diseases related to suboptimal diet and physical inactivity is enormous. It has been estimated that these lifestyle factors contribute to approximately 20% of deaths in the United States (1). Incidence of atherosclerotic cardiovascular disease, overweight and obesity, elevated blood pressure and lipid levels, diabetes, osteoporosis, and cancer is increased by unhealthy lifestyles (2-8). Multiple lifestyle factors, such as physical inactivity; excessive intake of calories, sodium, saturated fat, and cholesterol; and inadequate intake of fruits, vegetables, and low-fat dairy products, are etiologically related to the development of these diseases (4, 5, 8-10). To reduce the burden of chronic disease, increased physical activity and changes in diet are needed, yet few intervention studies have attempted to achieve many lifestyle changes simultaneously. The PREMIER randomized trial tested the effects of 2 multicomponent behavioral interventions on blood pressure (11). Both interventions promoted increased physical activity, weight loss, and reduced sodium intake, each of which is recommended by the 2005 Dietary Guidelines Scientific Advisory Committee (12). One intervention also added the Dietary Approaches to Stop Hypertension (DASH) diet (13). This diet, which is high in fruits, vegetables, and low-fat dairy products and low in saturated fat, total fat, and cholesterol, meets each of the major nutrient recommendations that were established by the Institute of Medicine (14-18). We report the effects of the PREMIER interventions on lifestyle changes and blood pressure status at 18 months. The main results of PREMIER, namely change in blood pressure at 6 months, were reported previously (11). Methods The PREMIER study design and rationale (19) and intervention methods (11) have been described previously. The institutional review boards at each clinical center; an external protocol review committee appointed by the National Heart, Lung, and Blood Institute (NHLBI); and the NHLBI reviewed and approved the protocol (available at www.kpchr.org/public/premier/intervention/default.asp). The NHLBI also appointed a data and safety monitoring board to monitor the trial. Each participant provided written informed consent. The trial was conducted from January 2000 through November 2002. Study Participants Participants were generally healthy adults, age 25 years or older, who had prehypertension or stage 1 hypertension and met the Joint National Committee VI (JNC VI) criteria for a 6-month trial of nonpharmacologic therapy (2). Targeted recruitment methods were used to ensure adequate representation of clinically important subgroups, in particular, African-American persons. Specific methods varied from site to site but included direct mailings, radio and newspaper advertisements, and networking within the local African-American communities. Eligibility criteria included not taking antihypertensive medication and having a systolic blood pressure of 120 to 159 mm Hg and a diastolic blood pressure of 80 to 95 mm Hg, based on the average of 3 screening visits. Persons with prehypertension (systolic blood pressure of 120 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg) were included because of the excess risk for cardiovascular disease in those with blood pressure within this range (20). Major exclusion criteria were a body mass index less than 18.5 kg/mg2 or greater than 45.0 kg/m2, use of antihypertensive drugs or other drugs that affect blood pressure, JNC VI risk category C (target organ damage or diabetes), use of prescription weight loss medications, previous cardiovascular event, congestive heart failure, angina, cancer, and consumption of more than 21 alcoholic drinks per week. Trial Conduct Eligible participants were randomly assigned, with equal probability, to 1 of 3 groups: an advice only comparison group (advice only); an intervention group that targeted established, guideline-recommended lifestyle recommendations (established) (2); or an intervention group targeting the established recommendations and adding the DASH dietary pattern (established plus DASH) (13). Computer-generated treatment assignments were stratified by clinic and hypertension status and were assigned in blocks of varying sizes to provide balance over time. The actual assignments were administered by using a password-protected, Web-based application developed by the coordinating center and accessible only by authorized individuals. All clinic measurement staff were blinded to treatment assignment, and all intervention staff were blinded to clinic measurements. Hypertension was defined by using the JNC VI criteria for hypertension treatment: an average systolic blood pressure of 140 mm Hg, a diastolic blood pressure greater than 90 mm Hg, or use of antihypertensive medication. Normal blood pressure was defined as systolic blood pressure less than 120 mm Hg, diastolic blood pressure less than 80 mm Hg, and no use of antihypertensive medication (21) (Figure). Intervention was provided by masters degreelevel counselors (dietitians and health educators trained in behavioral methods). The counselors were centrally trained before the start of the study, attended annual 3-day training sessions, and participated in monthly conference calls. Figure. Flow diagram of enrollment, measurements, and visit completion. Advice Only Group Participants in the advice group received advice to follow the National High Blood Pressure Education Program lifestyle recommendations for blood pressure control (2). Lifestyle recommendations included reducing weight (if overweight), following a reduced-sodium diet, engaging in regular moderate-intensity physical activity, and eating a heart-healthy diet, including the DASH diet. This advice was provided in two 30-minute individual sessions, 1 immediately after random assignment and 1 after the 6-month data collection visit. A PREMIER counselor reviewed the guidelines with the participant and provided printed educational materials and information about community resources. This intervention did not include advice to keep a food or exercise diary. Behavioral Interventions in the Established and Established plus DASH Groups Participant goals for the established and established plus DASH groups included weight loss of at least 6.8 kg (15 lb) for those with a body mass index of 25 kg/m2 or greater, at least 180 minutes per week of moderate-intensity physical activity, no more than 100 mmol per day of dietary sodium, and alcohol consumption of no more than 30 mL (1 oz) per day (2 drinks) for men and 15 mL (0.5) oz per day (1 drink) for women. Participants assigned to the established plus DASH group (but not those in the established group) also received counseling on the DASH diet, with goals for increased consumption of fruits and vegetables (9 to 12 servings/d) and low-fat dairy products (2 to 3 servings/d) and reduced consumption of saturated fat ( 7% of energy) and total fat ( 25% of energy). The intervention format, contact pattern, and behavior change strategies for the established and established plus DASH groups were identical. During the first 6 months, participants in both behavioral intervention groups attended 14 group sessions and 4 individual sessions; during months 7 to 18, they attended monthly group sessions supplemented with 3 individual counseling sessions. Throughout the trial, participants in the established and established plus DASH groups (but not those in the advice group) kept food diaries, monitored dietary calorie and sodium intakes, and recorded minutes of physical activity. Self-monitoring was used to provide individualized feedback, reinforcement, problem solving, and support. Social support for initial behavior changes and maintenance of change was provided during the group sessions. More detailed descriptions of the behavorial intervention methods are available (22). Measurements Blood pressure was assessed twice at each measurement, and systolic and diastolic blood pressures were calculated by using the mean of all available measurements (4 sets before random assignment, 3 sets at 6 and 18 months, and 1 set at 3 and 12 months). For 4 participants who were started on antihypertensive drug therapy between the 12- and 18-month visits, we obtained an official set of blood pressure measurements before initiation of therapy and used these as our 18-month blood pressure values for analysis. A similar procedure was used to obtain the 6-month blood pressure value for the 1 participant who began taking antihypertensive drugs between the 3- and 6-month visits. Two 24-hour dietary recalls, 1 obtained on a weekday and the other obtained on a weekend, were collected at baseline and at 6 and 18 months by telephone interview (23). Intakes of nutrients and food groups were calculated by using the Nutrition Data System for Research, version NDS-R 1998 (University of Minnesota, Minneapolis, Minnesota). Urinary excretion of sodium (reflecting salt intake) and potassium (reflecting fruit and vegetable intake) was obtained from 24-hour urinary collections at baseline a

Effects of Diet and Sodium Intake on Blood Pressure: Subgroup Analysis of the DASH-Sodium Trial

Although epidemiologic data show a direct relation between dietary sodium intake and blood pressure at the population level (1, 2), some experts question the universality of the findings and oppose public health recommendations to decrease sodium intake in the general population (3). Certainly, results from reports on the relationship between sodium and blood pressure among major subgroups vary considerably. Several studies suggest that African Americans and older adults have heightened salt sensitivity (greater blood pressure response to sodium intake) (4-6). Some evidence also indicates increased salt sensitivity in women (7), although other studies do not support this claim (4, 5). The association of sodium intake with cardiovascular morbidity and mortality varies by overweight status (8), perhaps reflecting a differential effect of sodium on blood pressure in overweight persons. Finally, higher dietary intakes of potassium and calcium have been shown to blunt the pressor effects of dietary sodium (9, 10). Dietary factors other than sodium also directly affect blood pressure, and these effects also appear to vary across subgroups. In the Dietary Approaches to Stop Hypertension (DASH) Trial, for example, a diet that had reduced total and saturated fat and was rich in fruits, vegetables, and low-fat dairy foods (the DASH diet) substantially decreased blood pressure compared with a more typical U.S. diet, in the absence of weight change and at sodium intakes approximating current U.S. consumption (11, 12). These effects persisted across all subgroups and were especially pronounced among hypertensive persons, African Americans, and persons who did not drink alcohol (13). The DASH-Sodium Trial examined the effects of reduced sodium intake in the context of the DASH diet and a more typical U.S. diet (14). In that study, highly significant decreases in blood pressure were observed with decreased sodium intake in participants following either diet, and the DASH diet decreased blood pressure at sodium intakes well below the current U.S. average. These results were observed overall and in subgroups defined by ethnicity, sex, and hypertension status (15). We report on more detailed subgroup analyses from the DASH-Sodium Trial, including results for subgroups defined by age, obesity, waist circumference, alcohol intake, and baseline sodium intake. We also report the results of multivariate analyses that demonstrate how these effects vary across subgroups defined jointly by age, ethnicity, sex, and hypertension status. Methods Study Design The DASH-Sodium Trial was a multicenter, randomized feeding trial comparing the effects on blood pressure of three levels of sodium intake and two dietary patterns. The 412 participants were 22 years of age or older and had systolic blood pressures of 120 to 159 mm Hg and diastolic blood pressures of 80 to 95 mm Hg (15). The three levels of sodium intake (lower, intermediate, and higher) varied according to energy intake in a ratio of 1:2:3; target intakes were 50, 100, and 150 mmol/d, respectively, for a 2100-kcal diet. The dietary patterns were a control diet, typical of what many Americans eat, and the DASH diet, which emphasizes fruits, vegetables, and low-fat dairy foods; includes whole grains, poultry, fish, and nuts; and is reduced in fats, red meat, sweets, and sugar-containing beverages (11, 14). Participants were recruited in four separate feeding cohorts and were randomly assigned to one of the two dietary patterns by using a parallel-group design. They then ate their assigned diet for three consecutive 30-day intervention feeding periods, during which sodium intake varied among the three levels by a randomly assigned sequence (Figure). Participants ate the control diet at the higher sodium intake during a 2-week run-in period. During the three intervention periods, participants received all their food in the context of the study and were asked not to eat any nonstudy food. Individual energy intake was adjusted to keep body weight stable. Figure. Design of the Dietary Approaches to Stop Hypertension (DASH)-Sodium Trial. Exclusion criteria were heart disease, renal insufficiency, poorly controlled hyperlipidemia or diabetes mellitus, diabetes requiring insulin, special dietary requirements, intake of more than 14 alcoholic drinks/wk, or use of antihypertensive drugs or other medications that would affect blood pressure or nutrient metabolism. The study was approved by the human subjects committees of the clinical centers and coordinating center, and participants gave informed consent. Measurement Protocol Trained staff measured blood pressure at each of three screening visits, on 2 days during the run-in period, and on 5 of the last 9 days of each intervention feeding period. Interim blood pressures were assessed once during each of the first 3 weeks of each intervention feeding period. During screening and the last week of each intervention feeding period, a 24-hour urine collection was obtained. Height and weight were measured, and body mass index was calculated. Baseline physical activity was measured by using a 7-day physical activity recall interview (16). Information on education level, income, alcohol consumption, and family history was obtained by using a questionnaire. Baseline blood pressure was defined as the average of the five preintervention blood pressures. End-of-feeding blood pressures were defined as the average of the five blood pressures at the end of each 30-day intervention feeding period. If no end-of-feeding blood pressure values were available (49 of 1236 possible cases), interim (n = 9) or screening (n = 40) blood pressures were used to impute end-of-feeding blood pressures. Definitions of Subgroups Ethnicity was categorized as African American versus other (primarily non-Hispanic white). Participants were considered hypertensive if their untreated baseline systolic blood pressure was 140 mm Hg or greater and their diastolic blood pressure was 90 mm Hg or greater. (Use of antihypertensive agents was an exclusion criterion [17].) Obesity was defined as body mass index of 30 kg/m2 or greater, and high-risk waist circumference was defined as greater than 102 cm in men and greater than 88 cm in women (18). Age, physical activity, baseline alcohol intake, baseline 24-hour urinary sodium level, and family income were dichotomized at the approximate median. Level of education was dichotomized as high school or less versus more than high school. Statistical Analysis The data were analyzed on an intention-to-treat basis. Given the differential effects of sodium on blood pressure observed in previous analyses among participants eating the DASH diet versus the control diet (15) and because power for subgroup analyses is more limited than for overall analysis, we focused our comparisons on the maximum contrasts (higher versus lower sodium intake with the control diet, DASH diet versus control diet at the higher sodium intake, and the combined effect of DASH diet and lower sodium intake versus control diet and higher sodium intake). We used generalized estimating equations (19) to fit linear models that predicted baseline and end-of-feeding blood pressures as a function of diet (DASH vs. control), sodium level, and subgroup indicators. Different ways of modeling the dietsodium effects and their interactions with the subgroup indicators were used to test specific hypotheses. In particular, two-way interactions of the various dietsodium effects with ethnicity, sex, hypertension status, and age were analyzed to determine the incremental effect on blood pressure in each of these subgroups while controlling for the main and incremental effects of the other subgroups. This model allowed us to estimate various diet-sodium contrasts for each of the 16 subgroups defined by hypertension status, ethnicity, sex, and age. A second set of models examined subgroup variables in a bivariate manner and did not assume simple additivity of subgroup effects. Finally, unadjusted subgroup analyses included main effects and interactions for a single subgroup indicator. All analyses were performed by using the xtgee procedure in Stata software, version 5 (Stata Corp., College Station, Texas) (20) and included adjustment for baseline blood pressure, site, feeding cohort, and carryover effects. An exchangeable covariance matrix was assumed for the repeated measurements for each participant. Unless otherwise stated, a P value less than 0.05 was significant, and all confidence intervals are 95% confidence intervals. Because subgroup analyses were planned to interpret and elucidate the overall study results, they are not adjusted for multiple comparisons. Results Of the 412 participants who underwent randomization, 390 (95%) completed the 12-week intervention feeding period. Adherence to the study diets seemed excellent, and body weight remained stable over time (15). Table 1 shows baseline characteristics of the 412 participants. Mean urinary sodium excretion at screening was 155 mmol/d, a value higher than that found while participants ate higher-sodium diets (142 mmol/d). Table 1. Characteristics of Study Sample Several key subgroups were highly interrelated. Women made up 70% of African-American participants but only 39% of non-African-American participants. Women were more likely to be hypertensive than were men. The percentage of both men and women with hypertension increased sharply with age among non-African-American participants (21% of those 45 years of age vs. 47% of those >45 years of age) but was equally high among older and younger African Americans (43% of those 45 years of age vs. 45% of those >45 years of age). These correlations highlight the potential for confounding in our results and, hence, the importance of the multivariate-adjusted analyses. Effects of the DASH Diet Table 2 shows the effect on systolic blood pressure of the DASH diet compared with the control diet du

Human Melatonin Production Decreases With Age

The purpose of this study was to investigate the effects of time of year and demographic variables on the amplitude of melatonin production in normal human subjects. Melatonin production was estimated by measuring the overnight excretion of its major urinary metabolite, 6‐hydroxymelatonin. Urine was collected on three consecutive nights in the summer from a sample of 60 normal subjects balanced for sex and age. The collections were repeated in a subgroup during the winter. Melatonin production clearly declined with age but was not influenced by other demographic variables or by season of the year.

Weight Loss During the Intensive Intervention Phase of the Weight-Loss Maintenance Trial

BACKGROUND To improve methods for long-term weight management, the Weight Loss Maintenance (WLM) trial, a four-center randomized trial, was conducted to compare alternative strategies for maintaining weight loss over a 30-month period. This paper describes methods and results for the initial 6-month weight-loss program (Phase I). METHODS Eligible adults were aged > or =25, overweight or obese (BMI=25-45 kg/m2), and on medications for hypertension and/or dyslipidemia. Anthropomorphic, demographic, and psychosocial measures were collected at baseline and 6 months. Participants (n=1685) attended 20 weekly group sessions to encourage calorie restriction, moderate-intensity physical activity, and the DASH (dietary approaches to stop hypertension) dietary pattern. Weight-loss predictors with missing data were replaced by multiple imputation. RESULTS Participants were 44% African American and 67% women; 79% were obese (BMI> or =30), 87% were taking anti-hypertensive medications, and 38% were taking antidyslipidemia medications. Participants attended an average of 72% of 20 group sessions. They self-reported 117 minutes of moderate-intensity physical activity per week, kept 3.7 daily food records per week, and consumed 2.9 servings of fruits and vegetables per day. The Phase-I follow-up rate was 92%. Mean (SD) weight change was -5.8 kg (4.4), and 69% lost at least 4 kg. All race-gender subgroups lost substantial weight: African-American men (-5.4 kg +/- 7.7); African-American women (-4.1 kg +/- 2.9); non-African-American men (-8.5 kg +/- 12.9); and non-African-American women (-5.8 kg +/- 6.1). Behavioral measures (e.g., diet records and physical activity) accounted for most of the weight-loss variation, although the association between behavioral measures and weight loss differed by race and gender groups. CONCLUSIONS The WLM behavioral intervention successfully achieved clinically significant short-term weight loss in a diverse population of high-risk patients.

COPD in Never Smokers: Results From the Population-Based Burden of Obstructive Lung Disease Study

Background: Never smokers comprise a substantial proportion of patients with COPD. Their characteristics and possible risk factors in this population are not yet well defined. Methods: We analyzed data from 14 countries that participated in the international, population-based Burden of Obstructive Lung Disease (BOLD) study. Participants were aged ≥ 40 years and completed postbronchodilator spirometry testing plus questionnaires about respiratory symptoms, health status, and exposure to COPD risk factors. A diagnosis of COPD was based on the postbronchodilator FEV1/FVC ratio, according to current GOLD (Global Initiative for Obstructive Lung Disease) guidelines. In addition to this, the lower limit of normal (LLN) was evaluated as an alternative threshold for the FEV1/FVC ratio. Results: Among 4,291 never smokers, 6.6% met criteria for mild (GOLD stage I) COPD, and 5.6% met criteria for moderate to very severe (GOLD stage II+) COPD. Although never smokers were less likely to have COPD and had less severe COPD than ever smokers, never smokers nonetheless comprised 23.3% (240/1,031) of those classified with GOLD stage II+ COPD. This proportion was similar, 20.5% (171/832), even when the LLN was used as a threshold for the FEV1/FVC ratio. Predictors of COPD in never smokers include age, education, occupational exposure, childhood respiratory diseases, and BMI alterations. Conclusion: This multicenter international study confirms previous evidence that never smokers comprise a substantial proportion of individuals with COPD. Our data suggest that, in addition to increased age, a prior diagnosis of asthma and, among women, lower education levels are associated with an increased risk for COPD among never smokers.

Chronic Obstructive Pulmonary Disease in the Older Adult: What Defines Abnormal Lung Function?

Background: The Global Initiative on Obstructive Lung Disease stages for chronic obstructive pulmonary disease (COPD) uses a fixed ratio of the post-bronchodilator forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) of 0.70 as a threshold. Since the FEV1/FVC ratio declines with age, using the fixed ratio to define COPD may “overdiagnose” COPD in older populations. Objective: To determine morbidity and mortality among older adults whose FEV1/FVC is less than 0.70 but more than the lower limit of normal (LLN). Methods: The severity of COPD was classified in 4965 participants aged ⩾65 years in the Cardiovascular Health Study using these two methods and the age-adjusted proportion of the population who had died or had a COPD-related hospitalisation in up to 11 years of follow-up was determined. Results: 1621 (32.6%) subjects died and 935 (18.8%) had at least one COPD-related hospitalisation during the follow-up period. Subjects (n = 1134) whose FEV1/FVC fell between the LLN and the fixed ratio had an increased adjusted risk of death (hazard ratio (HR) 1.3, 95% CI 1.1 to 1.5) and COPD-related hospitalisation (HR 2.6, 95% CI 2.0 to 3.3) during follow-up compared with asymptomatic individuals with normal lung function. Conclusion: In this cohort, subjects classified as “normal” using the LLN but abnormal using the fixed ratio were more likely to die and to have a COPD-related hospitalisation during follow-up. This suggests that a fixed FEV1/FVC ratio of <0.70 may identify at-risk patients, even among older adults.

Caesarean section delivery and the risk of allergic disorders in childhood

Background The composition of the intestinal flora in young children, if unfavourable, may increase the susceptibility to allergic disorders. Beneficial intestinal microbes originate from the maternal vaginal tract and thus are more likely to be transferred during vaginal births than during Caesarean sections (C‐sections).