Resistance training increases total daily energy expenditure in disabled older women with coronary heart disease.

Physical activity energy expenditure (PAEE) is a determinant of prognosis and fitness in older patients with coronary heart disease (CHD). PAEE and total energy expenditure (TEE) are closely related to fatness, physical function, and metabolic risk in older individuals. The goal of this study was to assess effects of resistance training on PAEE, TEE, and fitness in older women with chronic CHD and physical activity limitations (N = 51, mean age: 72 + 5 yr). The study intervention consisted of a progressive, 6-mo program of resistance training vs. a control group condition of low-intensity yoga and deep breathing. The study interventions were completed by 42 of the 51 participants. The intervention group manifested a 177 +/- 213 kcal/day (+9%) increase in TEE, pre- to posttraining, measured by the doubly labeled water technique during a nonexercise 10-day period (P < 0.03 vs. controls). This was due to a 50 +/- 74 kcal/day (4%) increase in resting metabolic rate measured by indirect calorimetry (P < 0.01, P < 0.05 vs. controls) and a 123 +/- 214 kcal/day (9%) increase in PAEE (P < 0.03, P = 0.12 vs. controls). Resistance training was associated with significant increases in upper and lower body strength, but no change in fat-free mass, measured by dual X-ray absorptiometry, or left ventricular function, measured by echocardiography and Doppler. Women in the control group showed no alterations in TEE or its determinants. There were no changes between groups in body composition, aerobic capacity, or measures of mental depression. These results demonstrate that resistance training of 6-mo duration leads to an increase in TEE and PAEE in older women with chronic CHD.

Relationship between ghrelin and energy expenditure in healthy young women.

Ghrelin is a novel peptide that has been isolated from human and rat stomach tissues. Despite its known stimulatory effects on appetite and eating behavior, little information is available regarding its relationship with energy expenditure in normal-weight humans. To address this issue, we examined the relationship between serum ghrelin and resting metabolic rate (RMR), the thermic effect of food (TEF), fasting and postprandial respiratory quotient, physical activity level, peak aerobic capacity (VO(2 peak)), energy intake, and psychological measures of feeding behavior. We recruited 65 young healthy women and determined RMR and TEF by indirect calorimetry after a 12-h fast. Physical activity was determined by a leisure time physical activity questionnaire; VO(2 peak) was determined by bicycle ergometer test to exhaustion; energy intake was determined by a 24-h dietary recall; and food behavior was determined by a three-factor eating questionnaire. Our cohort showed a broad range of body mass index (range, 16.8-28.3 kg/m2), RMR (range, 820-1550 kcal/d), TEF (range, 74.4-136.5 kcal/d), and percent body fat (range, 14.0-37.7%). We noted significant inverse correlations between ghrelin and RMR (r = -0.350, P = 0.004) and TEF (r = -0.396, P = 0.001). These inverse correlations persisted after statistical control for both fat-free mass and fat mass (ghrelin vs. RMR partial, r = -0.284, P = 0.024; and ghrelin vs. TEF partial, r = -0.329, P = 0.01) and insulin levels (ghrelin vs. RMR partial, r = -0.255, P = 0.046; and ghrelin vs. TEF partial, r = -0.287, P = 0.024) using partial correlation analysis. We also observed a significant inverse correlation between ghrelin and daily caloric intake (r = -0.266, P = 0.032), but ghrelin levels were not significantly correlated with fasting (r = -0.002), postprandial respiratory quotient (r = -0.016), leisure time physical activity (r = 0.104), VO(2 peak) (r = 0.138), dietary disinhibition (r = -0.071), dietary restraint (r = 0.051), or feeling of general hunger (r = -0.028). These results suggest that higher levels of ghrelin are associated with low levels of resting and postprandial thermogenesis, which is independent of individual differences in fat-free mass and fat mass. Although speculative, serum ghrelin may play a role in the regulation of energy homeostasis by acting as a hormonal marker of increased energy efficiency.

Metabolic and behavioral characteristics of metabolically obese but normal-weight women.

A unique subset of individuals termed metabolically obese but normal weight (MONW) has been identified. These young women are potentially at increased risk for development of the metabolic syndrome despite their young age and normal body mass index. We seek to determine metabolic and behavioral factors that could potentially distinguish MONW women from young women with a normal metabolic profile.Ninety-six women were classified as MONW (n = 12) or non-MONW (n = 84) based on a cut point of insulin sensitivity (as estimated by the homeostasis model assessment). Potentially distinguishing phenotypes between groups measured included serum lipids, ghrelin, leptin, adiponectin, body composition and body fat distribution, resting and physical activity energy expenditure, peak oxygen uptake, dietary intake, dietary behavior, and family history and lifestyle variables. Despite a similar body mass index between groups, MONW women showed higher percent body fat, lower fat-free mass, lower physical activity energy expenditure, and lower peak oxygen uptake than non-MONW women. Plasma cholesterol level was higher in MONW women, whereas no differences were noted for other blood lipids, ghrelin, leptin, adiponectin, and resting energy expenditure. MONW women had lower dietary restraint scores than non-MONW women, but no differences were noted in disinhibition, hunger, and dietary intake. Stepwise regression analysis performed on all subjects showed that 33.5% of the unique variance of the homeostasis model assessment was explained with the variables of percentage of body fat (17.1%), level of dietary restraint (10.4%), and age (6%). Both metabolic and dietary behavioral variables contribute to the deleterious metabolic profile of MONW women. They display lower insulin sensitivity due potentially to a cluster of sedentary behavior patterns that contribute to their higher adiposity. Furthermore, cognitive attitudes toward food (i.e. dietary restraint) and concomitant lifestyle behaviors may play a role in regulating insulin sensitivity in MONW women.

Metabolic and body composition factors in subgroups of obesity: what do we know?

Obesity is thought to be a heterogeneous disorder with several possible etiologies; therefore, by examining subtypes of obesity we attempt to understand obesity's heterogeneous nature. The purpose of this review was to investigate the roles of metabolic, body composition, and cardiovascular disease risk in subtypes of obesity. We briefly consider two subtypes of obesity that have been identified in the literature. One subset of individuals, termed the metabolically healthy, but obese (MHO), despite having large amounts of fat mass compared with at risk obese individuals shows a normal metabolic profile, but remarkably normal to high levels of insulin sensitivity. Preliminary evidence suggests that this could be due at least in part to lower visceral fat levels and earlier onset of obesity. A second subset, termed the metabolically obese, but normal weight (MONW), present with normal body mass index, but have significant risk factors for diabetes, metabolic syndrome, and cardiovascular disease, which could be due to higher fat mass and plasma triglycerides as well as higher visceral fat and liver content. We also briefly consider the potential role of adipose and gastrointestinal hormonal profiles in MHO and MONW individuals, which could lead to a better understanding of potential factors that may regulate their body composition. This information will eventually be invaluable in helping us understand factors that predispose to or protect obese individuals from metabolic and cardiovascular disease. Collectively, a greater understanding of the MHO and MONW individual has important implications for therapeutic decision making, the characterization of subjects in research protocols, and medical education.

Reduction in obesity and coronary risk factors after high caloric exercise training in overweight coronary patients.

BACKGROUND: The majority of patients with coronary heart disease (CHD) are overweight. However, little weight loss occurs with participation in a standard cardiac rehabilitation (CR) program. METHODS: Fifteen overweight patients (average body mass index of 31.0 kg/m2) with CHD completed a 4-month exercise training program in a CR program. The exercise program consisted primarily of walking long duration (60-90 minutes per session) 5 to 7 days per week at a relatively low intensity of 50% to 60% of peak VO2. Measures of body composition by dual-energy x-ray absorptiometry, body fat distribution by computed tomography, plasma lipid-lipoprotein, glucose and insulin concentrations, and peak VO2 were obtained before and after the exercise intervention. Patients maintained an isocaloric diet throughout the study. RESULTS: Patients had reductions in total body weight (-4.6 kg), fat mass (-3.6 kg), percent body fat (-2.9%), and waist circumference (-5.6 cm) (all P <.001) while maintaining fat-free mass. Subcutaneous adipose tissue was reduced by 12% (P <.001) and visceral adipose tissue was lowered by 14% (P <.001). There were favorable changes in the lipid-metabolic profile with reductions in triglyceride levels (-23.7%), total cholesterol/HDL-C ratio (-14.3%), and fasting insulin levels (-22.3%) (all P <.05). Peak VO2 increased by 21.2% (P <.001). CONCLUSIONS: The present pilot study results suggest that a high caloric training exercise training program in the CR setting may be effective in promoting weight loss and improving coronary risk factors in overweight coronary patients. Although additional research with randomized control patients is needed, this alternative to traditional CR may be considered to maximize weight loss as part of a secondary prevention program.

Resistance training on physical performance in disabled older female cardiac patients.

PURPOSE: We evaluated the value of resistance training on measures of physical performance in disabled older women with coronary heart disease (CHD). METHODS: The study intervention consisted of a 6-month program of resistance training in a randomized controlled trial format. Training intensity was at 80% of the single-repetition maximal lift. Control patients performed light yoga and breathing exercises. Study participants included 42 women with CHD, all >or= 65 yr of age and community dwelling. Subjects were screened by questionnaire to have low self-reported physical function. The primary study measurements related to the performance of 16 household activities of the Continuous Scale Physical Functional Performance test (CSPFP). These ranged from dressing, to kitchen and cleaning activities, to carrying groceries and walking onto a bus with luggage, and a 6-min walk. Activities were measured in time to complete a task, weight carried during a task, or distance walked. Other measures included body composition, measures of aerobic fitness and strength, and questionnaire-based measures of physical function and depression score. RESULTS: Study groups were similar at baseline by age, aerobic capacity, strength, body composition, and in performing the CSPFP. After conditioning, 13 of 16 measured activities were performed more rapidly, or with increased weight carried, compared with the control group (all P < 0.05). Maximal power for activities that involved weight-bearing over a distance, increased by 40% (P < 0.05). CONCLUSIONS: Disabled older women with CHD who participate in an intense resistance-training program improve physical capacity over a wide range of household physical activities. Benefits extend beyond strength-related activities, as endurance, balance, coordination, and flexibility all improved. Strength training should be considered an important component in the rehabilitation of older women with CHD.

Is there a threshold of visceral fat loss that improves the metabolic profile in obese postmenopausal women?

It is presently unclear how much visceral adipose tissue (VAT) loss is needed to induce favorable metabolic changes. Cross-sectional studies have proposed that a threshold level of VAT exceeding 110 cm(2) in women induces deleterious changes in the metabolic profile. It is presently unclear, however, if significant decreases in VAT below this given threshold significantly improve the metabolic profile more as compared to decreases that remain below 110 cm(2). To examine whether achieving versus not achieving the proposed VAT threshold impacts differently on the metabolic profile in postmenopausal women, we examined the effects of a VAT loss below the 110-cm(2) threshold versus those individuals who remained higher than 110 cm(2) after a weight loss program. Twenty-five sedentary obese (baseline % body fat, 47.7% +/- 4.1%; [mean +/- SD]) postmenopausal women aged between 51 and 71 years (59.7 +/- 5.6 years) and displaying high baseline levels of VAT accumulation (223 +/- 45 cm(2)) were submitted to a 1-year weight loss program with weight stabilization periods before and after weight reduction. Based on their loss of VAT after weight loss, subjects were characterized as "attainers" (post VAT levels < 110 cm(2); average, 96 +/- 10 cm(2); n = 10) or "non-attainers" (post VAT levels > 110 cm(2); average, 171 +/- 34 cm(2); n = 15). We compared changes in (1) plasma lipid-lipoprotein levels, (2) insulin sensitivity (euglycemic/hyperinsulinemic clamp), and (3) supine resting blood pressure between groups who achieved these 2 distinct levels of VAT. Attainers showed a 2-fold greater loss of VAT compared to non-attainers (-51.5% v -27.5%, P <.001). Attainers also showed a greater loss of body weight (-19.0% v -12.5%, P <.01) and fat mass (-34.8% v -18.4%, P <.001) after the program compared to non-attainers. Despite significant differences in the loss of total fat and VAT after the weight loss program, attainers and non-attainers showed comparable improvements for plasma high-density lipoprotein-cholesterol (HDL-chol) levels (+62.5% v +50.0%, P = not significant [NS]), cholesterol/HDL-chol ratio (-45.5% v -36.5%, P = NS), insulin sensitivity (+34.1% v +23.2%, P = NS), and resting systolic (-6.9% v -5.1%, P = NS) and diastolic (-11.3% v -11.1%, P = NS) blood pressure. These results do not favor the idea that attaining levels of VAT below a threshold of 110 cm(2) is necessary to favorably improve the metabolic profile in obese postmenopausal women. Achieving or not the proposed threshold of VAT, independently of baseline values, appears to yield similar metabolic improvements in obese postmenopausal women. More moderate losses of VAT appear to yield similar metabolic improvements as large losses.

Arg64 beta3-adrenoceptor variant and the components of energy expenditure.

OBJECTIVE: To determine Trp64Arg beta(3)-adrenoceptor genotype-specific differences in the components of energy expenditure. HYPOTHESIS: We hypothesized that resting metabolic rate (RMR) and physical activity levels would be lower and that thermic effect of feeding (TEF) would be higher in those with the Arg64 allele. RESEARCH METHODS AND PROCEDURES: RMR and TEF were measured by indirect calorimetry, physical activity by questionnaire, and total energy expenditure by the doubly labeled water method. Genotype-specific measures were compared using ANOVA and analysis of covariance (ANCOVA). RESULTS: RMR in Arg64 homozygotes was significantly lower than in Trp64 homozygotes [Arg64, 1373 +/- 259 kcal/d (n = 15) vs. Trp64Arg, 1538 +/- 238 kcal/d (n = 25) vs. Trp64, 1607 +/- 290 kcal/d (n = 22); p < 0.01]. TEF was significantly higher in Arg64 homozygotes compared with Trp64 homozygotes (Arg64, 359 +/- 28 kcal/d; Trp64Arg, 322 +/- 22 kcal/d; and Trp64, 279 +/- 23 kcal/d; p < 0.05). No differences were identified between genotypes in physical activity or in total energy expenditure. DISCUSSION: Our results suggest that the Arg64 beta(3)-adrenoceptor allele contributes significantly to the genetic variability in both RMR and TEF.

Impact of cardiovascular fitness and physical activity level on health outcomes in older persons.

It remains unclear whether health recommendations should focus on improving cardiovascular fitness or physical activity energy expenditure in older persons. Although the literature is not abundant in this area, we first examined the association between cardiovascular fitness and physical activity. It appears that cross-sectional studies support a positive association between cardiovascular fitness and physical activity energy expenditure, whereas intervention studies suggest that when aerobic exercise is implemented later in life, older individuals either do not change or decrease physical activity energy expenditure outside of the program. We also considered the impact of improvements in cardiovascular fitness and physical activity on some commonly measured health outcomes in older persons. Based on preliminary studies, it appears that improving cardiovascular fitness has a greater impact on various health outcomes, whereas increased physical activity is also associated with health benefits, although to a lesser extent. Further work should be devoted at elucidating the individual benefits of increasing cardiovascular fitness or physical activity on health outcomes in older persons. Such information will be useful in refining exercise prescription to improve health status, particularly in older persons.

Menopause, energy expenditure, and body composition.

OBJECTIVES: The effects of menopause transition on metabolic and cardiovascular disease risk in women are unclear. It is unknown whether estrogen deficiency, aging, or a combination of both factors are independent contributors to a worsening health profile in women. We considered the effects of menopause transition and hormone replacement therapy on body composition, regional body fat, energy expenditure, and insulin sensitivity. METHODS: A brief review of current literature that has considered the role of menopause transition and hormone replacement therapy on body composition, energy expenditure, and insulin sensitivity with an emphasis on longitudinal investigations. RESULTS: Preliminary evidence suggests that natural menopause is associated with reduced energy expenditure during rest and physical activity, an accelerated loss of fat-free mass, and increased central adiposity and fasting insulin levels. Hormone replacement therapy has been shown to attenuate these changes. Longitudinal and longer intervention studies are needed to confirm these initial findings. CONCLUSIONS: Menopause transition may represent a risky period in a woman's life, 'triggering' adverse metabolic and cardiovascular processes that predispose women to a greater incidence of obesity-related comorbidities. Dietary, exercise, and hormonal interventions specifically targeted at premenopausal women may help mitigate the worsening cardiovascular and metabolic risk profile associated with menopause.

No effect of the Trp64Arg beta(3)-adrenoceptor gene variant on weight loss, body composition, or energy expenditure in obese, caucasian postmenopausal women.

The Trp64Arg polymorphism in the beta(3)-adrenoceptor gene has been associated with increased prevalence of obesity, type 2 diabetes, and low rates of energy expenditure, although these findings are not unanimous. It is currently unknown if the presence of the Trp64Arg gene variant impedes the loss of body weight in obese, postmenopausal women via a reducing effect on energy expenditure. The objective of this study was to compare body composition and energy expenditure in carriers and noncarriers of the Trp64Arg variant in the beta(3)-adrenoceptor before and after weight loss. We measured body composition, total daily energy expenditure (TEE), resting metabolic rate (RMR), physical activity energy expenditure (PAEE), thermic effect of feeding (TEF), and respiratory quotient (RQ) in 34 obese, postmenopausal women (19 carriers and 15 noncarriers for the Trp64Arg variant) before and after a weight loss intervention. There were no differences in body composition or daily energy expenditure and its components between the 2 groups at baseline. There were significant reductions in body mass, body mass index (BMI), percent body fat, fat-free mass, and fat mass (main effect, all P <.0001) when analyzed with the 2 genotypes combined, but no significant differences between carriers and noncarriers with respect to change in these variables (group x time interaction term, all P >.05). Total energy expenditure tended to be reduced (490 kJ x d(-1), P =.13) in both groups following weight loss, but there was no significant group x time interaction term (P =.78), indicating no difference in the response of the 2 genotypes. There was a 9% reduction in RMR (611 kJ x d(-1), P <.001) when both groups were considered together, but no significant group x time interaction term (P =.84), suggesting that both groups responded in a similar manner to the weight loss intervention. PAEE and the TEF were not different following weight loss (both P >.60). There was a trend for RQ to be reduced after weight loss (P =.07), but there was no difference between carriers or noncarriers of the Trp64Arg variant (P =.58). In summary, we found that obese postmenopausal women who carry the Trp64Arg variant in the beta(3)-adrenoceptor had similar changes in body composition and energy expenditure to noncarriers of the variant in response to prolonged caloric restriction. These results suggest that the presence of the Trp64Arg variant in the beta(3)-adrenoceptor should not be a hindrance to weight reduction.