Biomedical subjects

Christopher L Gentile

Publications and source records attributed to Christopher L Gentile.

5 recordsLinked to original sources

PubMed2007

Modest weight gain is associated with sympathetic neural activation in nonobese humans.

We tested the hypothesis that modest, overfeeding-induced weight gain would increase sympathetic neural activity in nonobese humans. Twelve healthy males (23 +/- 2 years; body mass index, 23.8 +/- 0.7) were overfed approximately 1,000 kcal/day until a 5-kg weight gain was achieved. Muscle sympathetic nerve activity (MSNA, microneurography), blood pressure, body composition (dual energy X-ray absorptiometry), and abdominal fat distribution (computed tomography) were measured at baseline and following 4 wk of weight stability at each individual's elevated body weight. Overfeeding increased body weight (73.5 +/- 3.1 vs. 78.4 +/- 3.2 kg, P < 0.001) and body fat (14.9 +/- 1.2 vs. 18 +/- 1.1 kg, P < 0.001) in 42 +/- 8 days. Total abdominal fat increased (220 +/- 22 vs. 266 +/- 22 cm(2), P < 0.001) with weight gain, due to increases in both subcutaneous (158 +/- 15 vs. 187 +/- 12 cm(2), P < 0.001) and visceral fat (63 +/- 8 vs. 79 +/- 12 cm(2), P = 0.004). As hypothesized, weight gain elicited increases in MSNA burst frequency (32 +/- 2 vs. 38 +/- 2 burst/min, P = 0.002) and burst incidence (52 +/- 4 vs. 59 +/- 3 bursts/100 heart beats, P = 0.026). Systolic, but not diastolic blood pressure increased significantly with weight gain. The change in MSNA burst frequency was correlated with the percent increase in body weight (r = 0.59, P = 0.022), change in body fat (r = 0.52, P = 0.043) and percent change in body fat (r = 0.51, P = 0.045). The results of the current study indicate that modest diet-induced weight gain elicits sympathetic neural activation in nonobese males. These findings may have important implications for understanding the link between obesity and hypertension.

Adult↗

PubMed2006

Increased dietary protein and combined high intensity aerobic and resistance exercise improves body fat distribution and cardiovascular risk factors.

We investigated the effectiveness of two lifestyle modification programs of exercise training and nutritional intake (ad libitum) on improving body composition and disease risk in overweight/obese men and women. Sixty-three subjects were weight matched and assigned to one of three groups for a 12 wk intervention: (1) high-intensity resistance and cardiovascular training and a balanced diet (RC+BD, 40% CHO: 40% PRO; n=27, 16 female/11 male, age = 42 +/- 9 y); (2) moderate-intensity cardiovascular training and a traditional food guide pyramid diet (C+TD, CHO 50 to 55%; PRO 15 to 20%; FAT < 30%; n=19, 10 female/9 male, age = 43 +/- 10 y); and (3) an inactive control group (C, n=17, 5 female/12 male, age 43 +/- 11 y). RC+BD resulted in more favorable changes (P < 0.01) in percent body fat (-15.8% vs. -6.9%) and abdominal fat (-15.6% vs. -7.5%) compared to C+TD and C. Total cholesterol (-13.8%), LDL-cholesterol (-20.8%), and systolic blood pressure (-5.7%) declined (P > 0.05) in RC+BD, whereas C+TD and C remained unchanged. Our results suggest that RC+BD may be more effective than C+TD and C in enhancing body composition and lowering cardiovascular risk in obese individuals.

Adipose Tissue↗

PubMed2005

Fatness is a better predictor of cardiovascular disease risk factor profile than aerobic fitness in healthy men.

BACKGROUND: The prevalence of cardiovascular disease (CVD) is partly attributable to an inactive and/or overweight population. However, the independent association of body fatness and aerobic fitness with CVD risk factors is uncertain. We sought to determine whether fatness or fitness better predicted traditional CVD risk factors in men with broad fatness, aerobic fitness, and age ranges using 3 expressions of adiposity. METHODS AND RESULTS: In 135 carefully screened healthy men, we measured 18 established CVD risk factors, body mass index, total percent body fat, waist circumference, and maximal aerobic capacity. Body mass index, percent body fat, and waist circumference were consistently associated with all metabolic risk factors (r=-0.44 to 0.51, P<0.05) after partialling out the effects of aerobic fitness and age. Body mass index and waist circumference were also independently associated with selective hemodynamic risk factors (r=0.20 to 0.30, P< or =0.01). In contrast, aerobic fitness was independently associated with only selective metabolic risk factors (r=-0.21 to 0.19, P<0.05) and was not associated with any hemodynamic risk factors (P>0.05). Both aerobic fitness and body fatness were independently associated with selective hemostatic risk factors (r=-0.22 to -0.26, P< or =0.01; r=-0.32 to 0.48, P<0.05, respectively). Overall, fatness was more strongly and consistently associated with CVD risk factors than aerobic fitness. CONCLUSIONS: Body fatness is a better predictor of CVD risk factor profile than aerobic fitness in healthy men. Although habitual physical activity is an effective strategy for preventing CVD, elevated body fatness is associated with an adverse CVD risk factor profile independently of aerobic fitness.

Adipose Tissue↗

PubMed2003

Greater rate of decline in maximal aerobic capacity with age in endurance-trained than in sedentary men.

To determine the relation between habitual endurance exercise status and the age-associated decline in maximal aerobic capacity [i.e., maximal O(2) consumption (Vo(2 max))] in men, we performed a well-controlled cross-sectional laboratory study on 153 healthy men aged 20-75 yr: 64 sedentary and 89 endurance trained. Vo(2 max) (ml. kg(-1). min(-1)), measured by maximal treadmill exercise, was inversely related to age in the endurance-trained (r = -0.80) and sedentary (r = -0.74) men but was higher in the endurance-trained men at any age. The rate of decline in Vo(2 max) with age (ml. kg(-1). min(-1)) was greater (P < 0.001) in the endurance-trained than in the sedentary men. Whereas the relative rate of decline in Vo(2 max) (percent decrease per decade from baseline levels in young adulthood) was similar in the two groups, the absolute rate of decline in Vo(2 max) was -5.4 and -3.9 ml. kg(-1). min(-). decade(-1) in the endurance-trained and sedentary men, respectively. Vo(2 max) declined linearly across the age range in the sedentary men but was maintained in the endurance-trained men until approximately 50 yr of age. The accelerated decline in Vo(2 max) after 50 yr of age in the endurance-trained men was related to a decline in training volume (r = 0.46, P < 0.0001) and was associated with an increase in 10-km running time (r = -0.84, P < 0.0001). We conclude that the rate of decline in maximal aerobic capacity during middle and older age is greater in endurance-trained men than in their sedentary peers and is associated with a marked decline in O(2) pulse.

Adult↗

PubMed2003

Adiposity contributes to differences in left ventricular structure and diastolic function with age in healthy men.

We sought to examine the influence of adiposity in age-associated changes in the left ventricle (LV) in a cohort of 113 healthy men, aged 20-79 yr, by measuring LV structure and diastolic function (echocardiography), whole body composition, and regional adiposity (dual energy x-ray absorptiometry). Aging was associated with increased levels of adiposity, greater wall thickness to chamber radius ratio, LV concentric remodeling, and reduced LV diastolic function (all P < 0.05). Bivariate correlation analysis showed that mean LV wall thickness, a concentric LV morphology, and diastolic function were related to adiposity (r = -0.63 to 0.51; all P < 0.05). The relation between age and both mean LV wall thickness and concentric remodeling was reduced after controlling for percentage total body fat (by 38% and 54%, respectively), percentage abdominal fat (by 42% and 62%), and the abdominal/thigh fat ratio (by 35% and 46%). The diastolic function-age relation was reduced after controlling for percentage total body fat (by 35%), percentage abdominal fat (by 39%), and the abdominal/thigh fat ratio (by 29%). There were no apparent differences in the contribution of percentage total body fat, percentage abdominal fat, or abdominal/thigh fat to the association between age and LV structure/diastolic function. We conclude that increasing adiposity contributes to the LV remodeling/reduced diastolic function that occurs with aging in healthy men.

Abdomen↗