Hiroyuki Ohkubo

PPARG Genotype Accounts for Part of Individual Variation in Body Weight Reduction in Response to Calorie Restriction

Several studies indicate that expression of the peroxisome proliferator–activated receptor γ (PPARG) gene is influenced by calorie restriction. The aim of this study was to investigate whether PPARG gene variations are associated with weight reduction and changes in coronary heart disease (CHD) risk factors in response to a 14‐week calorie restriction. In total, 95 middle‐aged, Japanese women (BMI ≥25 kg/m2) enrolled as subjects for 14 weeks and attended weekly dietary lectures instructing them on how to consume a nutritionally balanced diet of 1,200 kcal/day. Eight single‐nucleotide polymorphisms (SNPs) in the PPARG gene (rs1801282 (Pro/Ala), rs2292101, rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were analyzed. Body weight decreased significantly (−7.7 ± 3.1 kg; −11.3 ± 4.4%) during the intervention. Six PPARG SNPs (rs2959272, rs1386835, rs709158, rs1175540, rs1175544, and rs1797912) were significantly associated with the weight reduction, with rs1175544 having the strongest association (P = 0.004). No differences across the rs1175544 genotypes were observed in any of the blood analyses or in blood pressure. In a multiple regression analysis, the rs1175544 genotypes accounted for 7% of the total weight reduction variance. These data suggest that one SNP of the PPARG genotype accounted for a significant portion of the total body weight reduction variance in response to a short‐term intervention consisting of calorie restriction; however, no relationship was found between these SNPs and the changes in CHD risk factors which accompanied weight loss.

Indirect lifestyle intervention through wives improves metabolic syndrome components in men

Objectives:It is well known that body weight loss through a direct (supervised) lifestyle intervention (LSI) improves obesity-related metabolic disorders. The purpose of this study was to investigate the effects of an indirect LSI on weight loss and metabolic syndrome (MetS) in spouses of LSI participants.Methods:A total of 104 men (abdominal circumference⩾85 cm; age, 52.1±9.3 years) were assigned to one of three groups: no intervention (NI, n=34), direct intervention (DI, n=34) or indirect intervention (II, n=36), the last of which consisted of subjects who did not participate in the direct LSI but whose wives did. Body weight and MetS components were measured before and after a 14-week intervention. Daily energy intake and activity-related energy expenditure were assessed before and during the intervention. The LSI program was mainly consisted of dietary modifications with a physical activity program.Results:No differences were observed across the three groups in any of the measures at baseline. Significant differences were observed among the groups in weight loss (NI, −0.7±1.4; DI, −6.2±3.3 and II, −4.4±3.7 kg) during the intervention. Along with the body weight reductions, significant improvements were observed in most of MetS components within the DI and II groups. When analyzing the spouse pairs in group II, significant correlations were observed in weight loss (r=0.57) and decreased total energy intake (r=0.54) between wives and husbands.Conclusions:Indirect LSI in abdominally obese men whose wives were undergoing LSI led to loss of weight and a decreased incidence of MetS, suggesting that indirect LSI may be an effective program for eliciting beneficial change in health status.

Epicardial Fat Tissue: Relationship with Cardiorespiratory Fitness in Men

PURPOSE To explore the influence of the epicardial fat (EF) tissue on aspects of heart rate recovery (HRR) and cardiorespiratory fitness (V O2peak) in middle-aged men. METHODS A cross-sectional analysis of EF thickness was performed on 101 overweight or obese men. The men were categorized into low-EF, moderate-EF, and high-EF groups on the basis of ventricular EF thickness, as measured by transthoracic echocardiography. V O2peak was assessed with a graded maximal cycle ergometric test, including measurement of HRR 2 min after test cessation to estimate parasympathetic activity, with assessment of several metabolic parameters. RESULTS Men in the highest and the middle EF thickness tertile had significantly slower recovery times than subjects in the lowest tertile, respectively (P < 0.05). Subjects with higher EF thickness were more likely to have impaired recovery and to reveal lower cardiorespiratory fitness than low-EF group subjects. There was a significant partial correlation, adjusted by age and body weight, between EF thickness and V O2peak (r = -0.25, P = 0.014). In the hierarchical multiple linear regression analyses, EF thickness was the strongest predicting variable associated with V O2peak in these population (beta = -1.182, P = 0.001). CONCLUSIONS Higher EF thickness in men is associated with lower HRR at 1 and 2 min, a representation of autonomic dysfunction and poor cardiorespiratory fitness. These data suggest that moderately obese men with thicker EF tissue demonstrate reduced cardiorespiratory fitness and a differing parasympathetic response to exercise testing, as compared with men with lower EF levels.

Obesity phenotype and intra-abdominal fat responses to regular aerobic exercise

AIM To examine the effects of obesity phenotype on abdominal fat responses to regular aerobic exercise. METHOD Fifty-seven obese men aged 34-70 years were divided into two groups based on baseline intra-abdominal fat (IF) area measured by computerized tomography: moderate (<200 cm(2)) IF (MIF; n=33, age: 52.9+/-10.6 [SD] yr, body mass index [BMI]: 29.2+/-3.1 kg/m(2)) or high (>or=200 cm(2)) IF (HIF; n=24, age: 53.5+/-9.5 yr, BMI: 30.3+/-3.1 kg/m(2)). The 12-week exercise program consisted primarily of aerobic exercise and met 3 days per week for 90 min per session. Weight, BMI, body composition (by dual-energy X-ray absorptiometry), IF and subcutaneous fat (SF) areas were measured before and after the program. RESULTS Regular aerobic exercise reduced weight by 2.3+/-2.2 kg in MIF and 3.2+/-3.0 kg in HIF. HIF reduced significantly more IF area than MIF (15.1+/-26.0 cm(2) in MIF and 43.3+/-41.9 cm(2) in HIF), and the difference remained significant after adjusting for baseline fat mass, weight change and total energy intake during the 12-week aerobic exercise. CONCLUSION Exercise-induced IF reduction may be remarkably influenced by obesity phenotype.

The effects of vigorous physical activity on intra-abdominal fat levels: A preliminary study of middle-aged Japanese men

AIM To examine the effects of vigorous physical activity (PA) on intra-abdominal fat (IF) levels in obese men. METHODS Thirty-seven obese men (mean age: 47.6+/-8.6 years) engaged in a 12-week aerobic exercise program on a regular basis (3 days/week). We divided them into low volume of vigorous PA group (n=19) or high volume of vigorous PA group (n=18), based on the median time spent (34.3min/week) in vigorous PA (over 6.1 metabolic equivalents assessed by a single-axis accelerometer) throughout the program. RESULTS Regular exercise reduced IF levels (measured by computed tomography) from 188.1+/-53.9cm(2) to 170.3+/-46.6cm(2) for the low volume of vigorous PA group and from 167.9+/-44.3cm(2) to 137.9+/-40.6cm(2) for the high volume of vigorous PA group. Two-way (time x group) ANOVA revealed no significant interactions for the IF level. However, correlation analysis for all participants showed that time spent in vigorous PA throughout the program significantly correlated to IF reductions after adjusting for initial levels of IF, vigorous PA and weight changes (r=-0.42, P=0.02). CONCLUSION This study suggests that vigorous PA may affect IF reductions in obese men.

Effect of weight loss on maximal fat oxidation rate in obese men

SUMMARY INTRODUCTION The hallmark features of obesity include insulin resistance and an impaired ability to oxidize lipids. As compared to exercise training, it remains relatively unclear if diet-induced weight loss can also induce fat metabolism. This study was undertaken to examine the effects of diet-induced weight loss on fat metabolism during a single session of exercise in middle-aged obese men. METHODS Fifteen obese men who were otherwise healthy (average age of 53.5 ± 6.9 yr and average body mass index of 27.8 ± 1.6 kg/m(2)) participated in a 12-wk weight loss program primarily consisting of dietary modification. Maximal fat oxidation (MFO) rates, MFO per lean body mass (MFOLBM) and insulin resistance (HOMA-IR) were measured before and after the program. Participants performed a 24-min graded exercise test on a cycle ergometer, with 15-W increments every 4 min. Expired gas analysis was performed by indirect calorimetry, and nonprotein respiratory quotient equations were used to calculate fat oxidation rates. RESULTS The weight (-8.3 ± 3.8 kg), fat mass (-4.5 ± 1.9 kg), and lean body mass (-3.8 ± 2.4 kg) (P < 0.001 for all measurements) of the participants were decreased at the end of the 12-wk program. The MFO tended to increase by 19% (P = 0.08) and MFOLBM significantly increased by 28.8% (P = 0.02). Although insulin resistance also significantly decreased by 49% (P < 0.001), changes in fat oxidation variables did not correlate with changes in insulin resistance. CONCLUSION Diet-induced weight loss improves fat metabolism with the improvement in insulin resistance.:

Air displacement plethysmography for estimating body composition changes with weight loss in middle-aged Japanese men.

Aim: To examine the degree to which air displacement plethysmography (ADP) can track body composition changes in response to weight loss in obese Japanese men. Method: 50 men, aged 30–65 years with a mean BMI of 30 kg/m2, were included in a 3-month weight loss program. Percentage of fat mass (%FM) was determined by dual energy X-ray absorptiometry (DXA) and ADP at baseline and month 3. Results: With 6.2 ± 4.3 kg of weight loss, %FM, as determined by DXA and ADP, significantly decreased by 3.9 ± 2.9% and 3.9 ± 3.3% respectively. There was no mean difference for change (Δ) in %FM between the two methods. DXA-derived Δ%FM significantly correlated with Δ%FM determined by ADP (R2 = 0.48, p < 0.01). Furthermore, the Bland-Altman plots demonstrated no systematic bias for Δ%FM (r = –0.20, p = 0.17). However, %FM by ADP (r = 0.42) at baseline and Δ%FM by ADP (r = –0.54) were significantly correlated to the differences between Δ%FM by DXA and ADP. Conclusion: These results suggest that ADP is comparably accurate for evaluating Δ%FM when compared with DXA, although there were proportional biases.