Ruth E. Brown

Relationship Between Obesity and Obesity-Related Morbidities Weakens With Aging

BACKGROUND A weak relationship exists between obesity and mortality risk in older populations, however, the influence of age on the relationship between obesity and morbidity is unclear. The objective of this study was to determine the influence of age on the relationship between obesity and cardiovascular disease, type 2 diabetes, dyslipidemia, and hypertension. METHODS Data from the Third National Health and Nutrition Examination Survey (1988-1994) were used. Individuals were classified into specific age (young: 18-40; middle: 40-65; old: 65-75; and very old: ≥75 years) and body mass index (BMI; 18.5-24.9, >25-29.9, ≥ 30kg/m(2)) categories. Cardiovascular disease, type 2 diabetes, dyslipidemia, and hypertension were categorized using measured metabolic risk factors, physician diagnosis, or medication use. RESULTS Age modified the relationship between BMI and cardiovascular disease (Age × BMI interaction, p = .049), dyslipidemia (Age × BMI interaction, p = .035 for men, p < .001 for women), and hypertension (Age × BMI interaction, p = .023) in women but not in men (p = .167). However, age did not modify the relationship between BMI and type 2 diabetes (Age × BMI interaction, p = .177). BMI was strongly associated with increased relative risk of cardiovascular disease, dyslipidemia, type 2 diabetes, and hypertension in the young and middle aged, however, the association between BMI and these metabolic conditions were much more attenuated with increasing age. CONCLUSION A stronger association between obesity and prevalent metabolic conditions exists in young and middle-aged populations than in old and very old populations. Longitudinal studies are needed to verify these findings and to confirm the benefits of weight loss on health across the life span.

All-cause and cardiovascular mortality risk in U.S. adults with and without type 2 diabetes: Influence of physical activity, pharmacological treatment and glycemic control.

AIMS This study determined the joint association between physical activity, pharmacotherapy, and HbA1c control on all-cause and cardiovascular disease (CVD) mortality risk in adults with and without type 2 diabetes (T2D). METHODS 12,060 adults from NHANES III and NHANES continuous (1999-2002) surveys were used. Cox proportional hazards analyses were included to estimate mortality risk according to physical activity, pharmacotherapy, and glycemic control (HbA1c <7.0%) status, with physically active, treated and controlled (goal situation) as the referent. RESULTS Compared to the referent, adults with T2D who were uncontrolled, or controlled but physically inactive had a higher all-cause mortality risk (p<0.05). Compared to the referent, only adults with T2D who were physically inactive had a higher CVD mortality risk, regardless of treatment or control status (p<0.05). Normoglycemic adults had a similar all-cause and CVD mortality risk as the referent (p>0.05). CONCLUSIONS Physical activity and glycemic control are both associated with lower all-cause and CVD mortality risk in adults with T2D. Adults with T2D who are physically active, pharmacologically treated, and obtain glycemic control may attain similar mortality risk as normoglycemic adults.

Individuals Underestimate Moderate and Vigorous Intensity Physical Activity

Background It is unclear whether the common physical activity (PA) intensity descriptors used in PA guidelines worldwide align with the associated percent heart rate maximum method used for prescribing relative PA intensities consistently between sexes, ethnicities, age categories and across body mass index (BMI) classifications. Objectives The objectives of this study were to determine whether individuals properly select light, moderate and vigorous intensity PA using the intensity descriptions in PA guidelines and determine if there are differences in estimation across sex, ethnicity, age and BMI classifications. Methods 129 adults were instructed to walk/jog at a “light,” “moderate” and “vigorous effort” in a randomized order. The PA intensities were categorized as being below, at or above the following %HRmax ranges of: 50–63% for light, 64–76% for moderate and 77–93% for vigorous effort. Results On average, people correctly estimated light effort as 51.5±8.3%HRmax but underestimated moderate effort as 58.7±10.7%HRmax and vigorous effort as 69.9±11.9%HRmax. Participants walked at a light intensity (57.4±10.5%HRmax) when asked to walk at a pace that provided health benefits, wherein 52% of participants walked at a light effort pace, 19% walked at a moderate effort and 5% walked at a vigorous effort pace. These results did not differ by sex, ethnicity or BMI class. However, younger adults underestimated moderate and vigorous intensity more so than middle-aged adults (P<0.05). Conclusion When the common PA guideline descriptors were aligned with the associated %HRmax ranges, the majority of participants underestimated the intensity of PA that is needed to obtain health benefits. Thus, new subjective descriptions for moderate and vigorous intensity may be warranted to aid individuals in correctly interpreting PA intensities.

The association between frequency of physical activity and mortality risk across the adult age span.

Objectives: To determine if the association between frequency of leisure-time physical activity and mortality risk differs across adulthood. Method: 9,249 adults from the NHANES III (1988-1994) were categorized as middle-aged (40-64 years), old (65-79 years) or very old (≥80 years), and as inactive (0 bouts of physical activity/week), lightly active (1-2 bouts/week), moderately active (3-4 bouts/week) or very active (5+ bouts/week). Results: In all age categories, lightly, moderately, and very active adults had a lower mortality risk compared to inactive adults (p < .001). In very old adults only, being very active was associated with a lower mortality risk compared to being lightly active (HR 0.80, 95% CI 0.64-0.98; p = .03) and moderately active (HR 0.80, 95% CI 0.65-0.98; (p = .03). Discussion: The association between physical activity frequency and mortality risk is strongest in very old adults. All adults and particularly very old adults may benefit from participating in physical activity five or more times a week.

Aspartame intake is associated with greater glucose intolerance in individuals with obesity

This study examined whether sucrose, fructose, aspartame, and saccharin influences the association between obesity and glucose tolerance in 2856 adults from the NHANES III survey. Aspartame intake significantly influenced the association between body mass index (BMI) and glucose tolerance (interaction: P = 0.004), wherein only those reporting aspartame intake had a steeper positive association between BMI and glucose tolerance than those reporting no aspartame intake. Therefore, consumption of aspartame is associated with greater obesity-related impairments in glucose tolerance.

Edmonton Obesity Staging System Prevalence and Association with Weight Loss in a Publicly Funded Referral-Based Obesity Clinic

Objectives. To determine the distribution of EOSS stages and differences in weight loss achieved according to EOSS stage, in patients attending a referral-based publically funded multisite weight management clinic. Subjects/Methods. 5,787 obese patients were categorized using EOSS staging using metabolic risk factors, medication use, and severity of doctor diagnosis of obesity-related physiological, functional, and psychological comorbidities from electronic patient files. Results. The prevalence of EOSS stages 0 (no risk factors or comorbidities), 1 (mild conditions), 2 (moderate conditions), and 3 (severe conditions) was 1.7%, 10.4%, 84.0%, and 3.9%, respectively. Prehypertension (63%), hypertension (76%), and knee replacement (33%) were the most common obesity-related comorbidities for stages 1, 2, and 3, respectively. In the models including age, sex, initial BMI, EOSS stage, and treatment time, lower EOSS stage and longer treatment times were independently associated with greater absolute (kg) and percentage of weight loss relative to initial body weight (P < 0.05). Conclusions. Patients attending this publicly funded, referral-based weight management clinic were more likely to be classified in the higher stages of EOSS. Patients in higher EOSS stages required longer treatment times to achieve similar weight outcomes as those in lower EOSS stages.

Specialist-Led Diabetes Registries and Prevalence of Poor Glycemic Control in Type 2 Diabetes: The Diabetes Registry Outcomes Project for A1C Reduction (DROP A1C).

OBJECTIVE To highlight the utility of a large patient registry to identify functionally refractory patients (persistent HbA1c ≥75 mmol/mol [9.0%]) with type 2 diabetes, identify their barriers to glycemic control, and implement barrier-specific care path strategies to improve glycemic control. RESEARCH DESIGN AND METHODS A working group developed a structured tool to optimize the collection of information on barriers to glycemic control and designed structured care paths to address each barrier. Participants were identified from a large Canadian registry and were assigned to a certified diabetes educator (CDE) as their case manager for a 12-month period to coordinate assessment of their barriers and to implement appropriate care path strategies. The primary outcome measure was the mean change in HbA1c from baseline at 12 months. RESULTS Overall, 3,662 refractory patients were initially identified of whom 1,379 were eligible for inclusion and 155 enrolled. The most common barrier categories participants identified were psychological/support (93%), socioeconomic (87%), and accessibility (82%), with high concordance (75–94%) between participant and CDE. No specific barriers were predictive of hyperglycemia. After implementation of barrier-specific care paths, the mean reduction in HbA1c at 12 months was 17 mmol/mol (1.5%; P < 0.01 vs. baseline) versus only 5 mmol/mol (0.5%) in the source cohort (n = 966) who continued with standard care. The incidence of severe hypoglycemia did not change significantly during the study. CONCLUSIONS In registry-identified hyperglycemic patients with type 2 diabetes, the use of barrier-specific care paths significantly improved glycemic control in otherwise refractory patients with persistently elevated HbA1c. Further studies using this strategy in other practice settings are warranted.

Calorie Estimation in Adults Differing in Body Weight Class and Weight Loss Status.

PURPOSE Ability to accurately estimate calories is important for weight management, yet few studies have investigated whether individuals can accurately estimate calories during exercise or in a meal. The objective of this study was to determine if accuracy of estimation of moderate or vigorous exercise energy expenditure and calories in food is associated with body weight class or weight loss status. METHODS Fifty-eight adults who were either normal weight (NW) or overweight (OW), and either attempting (WL) or not attempting weight loss (noWL), exercised on a treadmill at a moderate (60% HRmax) and a vigorous intensity (75% HRmax) for 25 min. Subsequently, participants estimated the number of calories they expended through exercise and created a meal that they believed to be calorically equivalent to the exercise energy expenditure. RESULTS The mean difference between estimated and measured calories in exercise and food did not differ within or between groups after moderate exercise. After vigorous exercise, OW-noWL overestimated energy expenditure by 72% and overestimated the calories in their food by 37% (P < 0.05). OW-noWL also significantly overestimated exercise energy expenditure compared with all other groups (P < 0.05) and significantly overestimated calories in food compared with both WL groups (P < 0.05). However, among all groups, there was a considerable range of overestimation and underestimation (-280 to +702 kcal), as reflected by the large and statistically significant absolute error in calorie estimation of exercise and food. CONCLUSIONS There was a wide range of underestimation and overestimation of calories during exercise and in a meal. Error in calorie estimation may be greater in overweight adults who are not attempting weight loss.

Composite Risk Scores

The following chapter will discuss the history and clinical utility of several different composite risk models. Composite risk models are used to combine the various known risk factors and translate them into a more easily interpretable risk value. The Framingham Risk Algorithm is among the oldest and most widely used risk scores for cardiovascular disease, and over the years, new cardiovascular disease risk algorithms, such as the Reynolds Risk Score and the Pooled Cohort Equations, have been developed. However, the applicability of these scores to ethnically and socioeconomically diverse populations has been questioned. As well, several lifetime cardiovascular disease models have been developed, but the clinical utility of assessing lifetime cardiovascular risk is still debated. Furthermore, different health organizations have developed several criteria for the metabolic syndrome, yet the clinical utility of the metabolic syndrome is still debated. In recent years, staging systems for obesity and cardiometabolic health have been developed to guide medical treatment, though due to their novelty, there is limited research on their effectiveness. However, for a given risk score, there are still individual differences in actual risk score, termed residual risk. This means that even if a patient achieves target levels of metabolic risk factors, some may still experience a cardiac event even if their predicted risk is low. This residual cardiovascular risk that is not accounted for by the risk models is true for all algorithms but can be reduced by adopting a healthy lifestyle or improving other important factors not accounted for by the algorithm. Finally, risk assessment is only valuable if the patient understands what that risk means, and therefore optimal risk communication between health professional and patient is vital for improving patient care. This review will describe the development and clinical utility of the Framingham Risk Score, the Reynolds Risk Score, the Pooled Cohort Equations, lifetime risk scores, the metabolic syndrome, the Edmonton Obesity Staging System, and the Cardiometabolic Disease Staging System. Residual cardiovascular risk and patient communication will also be discussed.