Warren D. Franke

Accuracy of Armband Monitors for Measuring Daily Energy Expenditure in Healthy Adults

INTRODUCTION There is a need to develop accurate devices for measuring daily energy expenditure under free-living conditions, particularly given our current obesity epidemic. PURPOSE The purpose of the present study was to evaluate the validity of energy expenditure estimates from two portable armband devices, the SenseWear Pro3 Armband (SWA) monitor and the SenseWear Mini Armband (Mini) monitor, under free-living conditions. METHODS Participants in the study (30 healthy adults aged 24-60 yr) wore both monitors for 14 consecutive days, including while sleeping. Criterion values for total energy expenditure (TEE) were determined using doubly labeled water (DLW), the established criterion standard method for free-living energy expenditure assessment. RESULTS The average TEE estimates were within 112 kcal·d−¹ for the SWA and within 22 kcal·d−¹ for the Mini, but the absolute error rates (computed as the average absolute value of the individual errors) were similar for the two monitors (SWA = 8.1% ± 6.8%, Mini = 8.3% ± 6.5%). Using intraclass correlation (ICC) analysis, significant agreements were found between the SWA and DLW estimates of energy expenditure (ICC = 0.80, 95% CI = 0.89-0.70) and between the Mini and DLW (ICC = 0.85, 95% CI = 0.92-0.76). Graphical plots of the DLW TEE values against the difference between DLW and monitor estimates of TEE showed that the agreement was consistent across a range of TEE values. CONCLUSIONS The SenseWear Pro3 and the SenseWear Mini armbands show promise for accurately measuring daily energy expenditure under free-living conditions. However, more work is needed to improve the ability of these monitors to accurately measure energy expenditure at higher levels of expenditure.

Relationship between cardiovascular disease morbidity, risk factors, and stress in a law enforcement cohort

It is unclear to what extent law enforcement officers (LEOs) experience increased prevalence of cardiovascular disease (CVD; defined as coronary heart disease, myocardial infarction, angina, or stroke) and, if so, whether perceived stress affects this relationship. First, self-reported CVD risk factors among currently employed male LEOs from 9 states (n = 2818) were compared to CVD risk factors among similarly-aged males with similar incomes in the same states (n = 8046). Second, CVD prevalence was compared among LEOs (n = 1791) and similarly-aged males with similar incomes (n = 2575) from four of these states. Finally, among the LEOs only, the possible effect of perceived stress on the relationship between CVD prevalence and CVD risk factors was assessed. LEOs reported higher prevalence of hypertension, hypercholesterolemia, tobacco use, and elevated body mass index. CVD prevalence did not differ significantly between the LEO group and the general population (2.3% ± 15% versus 3.1% ± 17%;P = 0.095). In the LEO-only group, the best predictors of CVD were: time in the profession (OR = 1.07; 95% CI = 1.03–1.11), perceived stress (OR = 1.05; 95% CI = 1.00–1.10), and hypertension (OR = 0.33; 95% CI = 0.18–0.62). In the LEO-only group, perceived stress was associated with CVD (P = 0.008), and three CVD risk factors were significantly affected by perceived stress: cholesterol, hypertension, and physical activity. Perceived stress was affected by duration of time in the profession (P = 0.004), independent of an age effect (P = 0.353). Among susceptible officers, perceived stress may contribute to CVD directly and through potentiating several CVD risk factors.

Perceptions of Technology Among Older Adults

Changes and advancements in technology have the potential to benefit older adults by promoting independence and increasing the ability to age in place. However, older adults are less likely to adopt new technology unless they see benefits to themselves. This study assessed the perceptions of 30 older adults in the Midwest concerning technology via three separate focus groups (i.e., independent apartment complex, a rural community, exercise program participants), which addressed a need in the literature (i.e., inclusion of oldest-old and rural individuals). The focus group questions included items such as what technology older adults currently used, desired improvements in technology, and the greatest challenges participants were facing or would face in the future. Overall, older adults were enthusiastic about learning new forms of technology that could help them maintain their independence and quality of life. Five themes emerged from all three focus groups: (a) Frustrations, Limitations, and Usability Concerns; (b) Transportation; (c) Help and Assistance; (d) Self-Monitoring; and (e) Gaming. The themes have important implications for future technology developed for older adults; in particular, older adults were willing and eager to adopt new technology when usefulness and usability outweighed feelings of inadequacy.

Endocrine and Lipid Responses to Chronic Androstenediol-Herbal Supplementation in 30 to 58 Year Old Men

Objective: The effectiveness of an androgenic nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogen was investigated in healthy 30 to 58 year old men. Design: Subjects were randomly assigned to consume a nutritional supplement (AND-HB) containing 300-mg androstenediol, 480-mg saw palmetto, 450-mg indole-3-carbinol, 300-mg chrysin, 1,500 mg gamma-linolenic acid and 1,350-mg Tribulus terrestris per day (n = 28), or placebo (n = 27) for 28 days. Subjects were stratified into age groups to represent the fourth (30 year olds, n = 20), fifth (40 year olds, n = 20) and sixth (50 year olds, n = 16) decades of life. Measurements: Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate specific antigen and lipid concentrations were measured before supplementation and weekly for four weeks. Results: Basal serum total testosterone, estradiol, and prostate specific antigen (PSA) concentrations were not different between age groups. Basal serum free testosterone concentrations were higher (p < 0.05) in the 30- (70.5 ± 3.6 pmol/L) than in the 50 year olds (50.8 ± 4.5 pmol/L). Basal serum androstenedione and dihydrotestosterone (DHT) concentrations were significantly higher in the 30- (for androstenedione and DHT, respectively, 10.4 ± 0.6 nmol/L and 2198.2 ± 166.5 pmol/L) than in the 40- (6.8 ± 0.5 nmol/L and 1736.8 ± 152.0 pmol/L) or 50 year olds (6.0 ± 0.7 nmol/L and 1983.7 ± 147.8 pmol/L). Basal serum hormone concentrations did not differ between the treatment groups. Serum concentrations of total testosterone and PSA were unchanged by supplementation. Ingestion of AND-HB resulted in increased (p < 0.05) serum androstenedione (174%), free testosterone (37%), DHT (57%) and estradiol (86%) throughout the four weeks. There was no relationship between the increases in serum free testosterone, androstenedione, DHT, or estradiol and age (r2 = 0.08, 0.03, 0.05 and 0.02, respectively). Serum HDL-C concentrations were reduced (p < 0.05) by 0.14 mmol/L in AND-HB. Conclusions: These data indicate that ingestion of androstenediol combined with herbal products does not prevent the formation of estradiol and dihydrotestosterone.

Cardiovascular disease morbidity in an Iowa law enforcement cohort, compared with the general Iowa population

It remains uncertain if law enforcement officers experience an elevated cardiovascular disease morbidity and, if so, whether their profession contributes to this incidence. Consequently, the self-reported incidence of cardiovascular disease (CVD) (coronary heart disease, myocardial infarction, stroke, coronary artery bypass graft surgery, angioplasty) and CVD risk factors (age, diabetes, elevated body mass index (> or = 27.8 kg.m-2), hypercholesterolemia, hypertension, tobacco use) in 232 male retirees, > or = 55 years of age, from the Iowa Department of Public Safety were compared with 817 male Iowans of similar age. CVD incidence was higher in the law enforcement officers than the general population (31.5% vs 18.4%, P < 0.001). Using multiple logistic regression, factors found to be associated with CVD included the law enforcement profession (odds ratio [OR] = 2.34; 95% confidence interval [95% CI] = 1.5-3.6), hypercholesterolemia (OR = 2.37; 95% CI = 1.7-3.3); diabetes (OR = 2.22; 95% CI = 1.4-3.6), hypertension (OR = 1.79; 95% CI = 1.3-2.5), tobacco use (OR = 1.67; 95% CI = 1.07-2.6), and age (OR = 1.06; 95% CI = 1.03-1.08). These results suggest that employment as a law enforcement officer is associated with an increased cardiovascular disease morbidity and this relationship persists after considering several conventional risk factors.

Cardiovascular and autonomic responses to lower body negative pressure

Abstract. This study tested the hypotheses that differences in the adrenergic, central venous pressure (CVP), cardiovascular, or baroreflex responses to lower body negative pressure (LBNP) or differences in body size would be associated with gender differences in orthostatic tolerance. Subjects (24 females, 22 males) underwent graded LBNP to −100 mmHg or presyncope. At rest, the males had higher SV (+ 21 ml·beat−1), cardiac output (+ 1.65 L·min−1), systolic blood pressure (+ 29 mmHg) and mean arterial pressure (+ 8 mmHg; all P < 0.05). Neither the CVP responses to LBNP to −60 mmHg, the Δforearm vascular conductance/ΔCVP with LBNP to −20 mmHg nor the Δheart rate/ΔCVP with LBNP of −30 to −60 mmHg differed between genders. LBNP tolerance was lower for the females than males (276 ± 12 vs 337 ± 14mmHg·min; LBNP tolerance index; P < 0.01) and, of the resting data, only gender was associated with LBNP tolerance (R2 = 20 %). Use of gender, the maximal change in HR with LBNP and the change in HR from 0 to −40 mmHg in a regression equation could explain 75 % of the variability in orthostatic tolerance. No cardiovascular parameter differed between genders in the two minutes preceding presyncope. In the last completed stage and at test termination, [epinephrine] and [norepinephrine] were higher in the men. These data suggest that the CVP, cardiovascular and baroreflex responses to graded LBNP are similar in men and women despite marked differences in LBNP tolerance. Differences in body size do not explain the gender difference although differences in the adrenergic responses at maximal LBNP may play a role.

Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30- to 59-year-old men.

The effectiveness of a nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogens from the ingested androgens was investigated in healthy 30- to 59-year old men. Subjects were randomly assigned to consume DION (300 mg androstenedione, 150 mg dehydroepiandrosterone, 540 mg saw palmetto, 300 mg indole-3-carbinol, 625 mg chrysin, and 750 mg Tribulus terrestris per day; n = 28) or placebo (n = 27) for 28 days. Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate-specific antigen (PSA), and lipid concentrations were measured before and throughout the 4-week supplementation period. Serum concentrations of total testosterone and PSA were unchanged by supplementation. DION increased (p < 0.05) serum androstenedione (342%), free testosterone (38%), dihydrotestosterone (71%), and estradiol (103%) concentrations. Serum HDL-C concentrations were reduced by 5.0 mg/dL in DION (p < 0.05). Increases in serum free testosterone (r2 = 0.01), androstenedione (r2 = 0.01), dihydrotestosterone (r2 = 0.03), or estradiol (r2 = 0.07) concentrations in DION were not related to age. While the ingestion of androstenedione combined with herbal products increased serum free testosterone concentrations in older men, these herbal products did not prevent the conversion of ingested androstenedione to estradiol and dihydrotestosterone.

Coronary heart disease risk factors in employees of Iowa's Department of Public Safety compared to a cohort of the general population

The prevalence of coronary heart disease (CHD) risk factors in law enforcement personnel compared to that in the general population was studied by determining the predicted 10-year risk for developing CHD (CHD10, expressed as %) in subjects from the Iowa Department of Public Safety and comparing it to the average CHD10 for similarly aged subjects in the Framingham Heart Study cohort. The Iowa data included measures on 388 men from 30 to 64 years old, 246 of whom were measured in 1980-1981 and again in 1992-1993. The CHD10 came from an algorithm developed using the Framingham data; it included measures of age, gender, cholesterol, HDL-C, systolic blood pressure, smoking habit, glucose level, and left ventricular hypertrophy (ECG criteria). For this group, average CHD10 was reported by age in five-year increments [Circulation 83:356, 1991]. The Iowa subjects (n = 388) did not show a statistically significant difference in CHD10 from the reference population (8.9% versus 7.9%). The change with age was very similar in the two groups: for Iowa (n = 388) the estimate was CHD10 = -16.5 + .59 (age); for Framingham it was CHD10 = -17.5 + .60 (age). The change in individual risk factors with time was also similar in both groups; the per year change in CHD10 in the Iowa subjects, which was measured twice (n = 246, 0.63%), did not differ statistically from the 0.60% change predicted by the Framingham model. These results suggest that, for the risk factors considered here, the 10-year probability of developing CHD among Iowa law enforcement personnel is similar to that found in the Framingham population.

Relationship between physical activity and risk factors for cardiovascular disease among law enforcement officers.

This investigation examined the associations between exercise habits, measures of physical fitness, and 10-year cardiovascular disease risk (CVD10, expressed as %) among 470 law enforcement officers of differing ages (range = 21 to 63 y). Only 32% of this group exercised regularly (> or = 3 days/week, > or = 20 min/session, > or = preceding 4 weeks). Only exercising subjects > 48 years old exhibited a significantly (P < .01) lower 10-year risk of a CVD event than their inactive peers (12.2 +/- 5.6 vs 16.3 +/- 6.9%, mean +/- SD). At all ages, the peak oxygen consumption per unit time was higher (50.1 +/- 6.7 vs 44.8 +/- 6.1 mL.kg-1.min-1) in the exercising than in the nonexercising group. Exercising subjects < or = 36 years old were significantly (P < .05) leaner than nonexercisers (16.3 +/- 5.5 vs 19.6 +/- 5.5% body fat, respectively) and had greater muscular endurance (45 +/- 9 vs 40 +/- 9 60-s sit-ups, respectively). These data suggest that exercise reduces CVD risk by modifying major CVD risk factors only in law enforcement officers > 48 years old.

Independent and combined influence of physical activity and perceived stress on the metabolic syndrome in male law enforcement officers.

Objective: To examine the independent and combined interrelationships among physical activity, perceived stress, and the metabolic syndrome in law enforcement officers (LEOs). Methods: Perceived stress, self-reported physical activity, and metabolic syndrome risk factors were assessed in 386 white male LEOs. Results: Among the LEOs, 23.1% had the metabolic syndrome. The metabolic syndrome was not significantly associated with perceived stress (r = 0.047) whereas physical activity was (r = −0.225, P < 0.0001). The odds ratios (95% CI) for possessing the metabolic syndrome in the low and moderate physical activity groups compared to the high physical activity group were 3.13 (95% CI = 1.56 to 6.26) and 2.30 (95% CI = 1.29 to 4.09), respectively. Conclusions: Regardless of stress level, physical inactivity is an important risk factor in the metabolic syndrome among this unique occupational group.