Tomohiro Okura

Association of polymorphisms in the estrogen receptor α gene with body fat distribution

OBJECTIVE: To examine whether polymorphisms of the estrogen receptor (ER) α gene are associated with body fat distribution.DESIGN: Cross-sectional, epidemiological study of two single-nucleotide polymorphisms, a T → C (PvuII) and an A → G (XbaI), in the first intron of the ERα gene.SUBJECTS: A total of 2238 community-dwelling middle-aged and elderly Japanese population (age: 40–79 y).MEASUREMENTS: The ERα genotypes (by automated fluorescent allele-specific DNA primer assay system), anthropometric variables, fat mass (FM) and percentage FM (%FM) (by dual-energy X-ray absorptiometry).RESULTS: FM and waist were inversely associated with age (r=−0.630 and −0.504, respectively) in women with the GG genotype. On the other hand, waist circumference of the AA genotype was positively correlated with age (r=0.231). Thus, for middle-aged women (40–59 y) with the AG or GG genotype body mass index (BMI), %FM, FM, waist, hip and waist-to-hip ratio (WHR) were larger than those with the AA genotype. In particular, FM and waist were greater by 20% and 9%, respectively, for the GG genotype, compared to the AA genotype. Alternatively, FM and waist were smaller by 18% and 6%, respectively, in older women with the GG genotype, compared to the AA genotype. No effect was found among the A → G polymorphisms for men. For both genders, no difference was found in any variables among the TT, TC and CC genotypes with the exception of BMI of older men (60–79 y).CONCLUSION: No association was found between the ERα gene polymorphisms and body fat distribution in men. For women, the A → G polymorphism, in particular the GG genotype, may contribute to the development of upper-body obesity in middle-aged individuals, but may serve to decrease the whole-body and abdominal fat tissue of older individuals.

Square-stepping exercise versus strength and balance training for fall risk factors.

Background and aims: Feasible and low-cost exercise programmes targeting fall risk factors may decrease the risk of falling in older adults. The purpose of this study was to compare the effects of square-stepping exercise (SSE) training, which is a new and low-cost method designed to improve lower-extremity functional fitness, with strength and balance (SB) training. Methods: The study included 39 community-dwelling adults aged 65 to 74 years. The participants were randomized to either group SSE (n=20) or SB (n=19). They engaged in 70-min group exercise sessions twice a week for 12 weeks. The efficacy of the program was measured with both a 9-item test battery for assessment of physical performance and self-reported scales (fear of falling, pleasure in exercise, perceived health status). Fall incidence was followed up for 14 months. Results: The results of a 2-way ANOVA revealed that the time effect in 7 of the 9 performance tests was significant, although group-by-time interactions were not. No significant changes were observed in the self-reported scales. During the 14-month follow-up period, 7 falls in 6 participants in the SSE group and 12 falls in 11 participants in the SB group were reported. The incidence rate per person in the SSE group (30.0%) was not significantly different from that in the SB group (57.9%). The rate of falls per trip [falls/(falls + trips)] in the SSE group (17.1 %) was significantly lower than in the SB group (50.0%). Conclusions: SSE is as equally effective as SB training in improving lower-extremity functional fitness. SSE may also be recommended for older adults, due to its low cost and effectiveness.

Effects of aerobic exercise and obesity phenotype on abdominal fat reduction in response to weight loss

OBJECTIVE:To test the effects on abdominal fat reduction of adding aerobic exercise training to a diet program and obesity phenotype in response to weight loss.DESIGN:A prospective clinical trial with a 14-week weight-loss intervention design.SETTING AND PARTICIPANTS:In total, 209 overweight and obese women were assigned to four subgroups depending on type of treatment and the subjects obesity phenotype: diet alone (DA) with intra-abdominal fat (IF) obesity (≥mean IF area), diet plus exercise (DE) with IF obesity, DA with abdominal subcutaneous fat (ASF) obesity (<mean IF area) and DE with ASF obesity. Abdominal fat areas were evaluated by CT scans, with values adjusted for selected variables.RESULTS:Values were adjusted for age, menopausal status and change in body weight and total fat mass. The IF reductions were significantly (P<0.0001) greater in subjects with IF obesity phenotype (−45.1 cm2) compared to the ASF obesity phenotype (−22.2 cm2). The ASF reductions were significantly (P<0.001) greater for subjects with ASF obesity (−74.5 cm2) compared to IF obesity (−55.5 cm2). For IF obesity, the IF reduction was significantly (P<0.01) greater in the DE group (−49.3 cm2) than in the DA group (−37.8 cm2).CONCLUSION:These results suggest that for individuals with IF obesity, the efficacy on reducing IF of adding aerobic exercise training to a diet-alone weight-reduction program is more prominent (−49.3 cm2/−37.8 cm2=1.3 times) compared with DA. Moreover, abdominal fat reduction was found to be modified by obesity phenotype in response to weight loss.

A novel exercise for improving lower-extremity functional fitness in the elderly.

Background and aims: Many falls in the elderly are caused by tripping. After tripping, a certain level of lower-extremity functional fitness is necessary, in order to make protective responses and to avoid falling. The purpose of this study was to test whether our new exercise program (a square-stepping exercise: SSE) would improve lower-extremity functional fitness in the elderly. Methods: Fifty-two individuals aged 60–80 years were divided into two groups (non-randomized control design); SSE (n=26) and controls (n=26). Lower-extremity functional fitness was defined as standing up from a lying position (agility), chair-stand in ten seconds (leg power), walking round two cones (locomotion speed), sit-and-reach (flexibility) and single-leg balance with eyes closed (balance). The SSE group participated in a six-month regimen of SSE once a week. SSE was performed on a thin mat of 250 cm by 100 cm, partitioned into 40 small squares (25 cm each side). SSE included not only forward steps but also backward, lateral and oblique steps, and step patterns were progressively made more complicated. Controls maintained their usual lifestyles. Results: In the SSE group, significant improvements were observed in agility, leg power, locomotion speed, flexibility and balance. No significant changes were detected in any tests in the control group. Conclusions: The SSE program improved lower-extremity functional fitness, lack of which constitutes a risk factor for falls in the elderly. This program should be tested further to determine if it can effectively reduce the incidence of falls in the elderly.

Association of the mitochondrial DNA 15497G/A polymorphism with obesity in a middle-aged and elderly Japanese population

Although polymorphism of the mitochondrial DNA 15497guanine/adenine (Mt15497G→A) leads to the Gly251Ser amino acid replacement on human cytochrome b, it is unknown whether functional alteration of the mitochondrion is induced by the Gly251Ser replacement. To see if an association exists between the Mt15497G→A polymorphism and obesity, we examined differences in body size, body composition, and regional body fat distribution between the two genotypes in middle-aged and elderly Japanese individuals (825 women and 906 men). The Mt15497 genotype was determined with an automated colorimetric allele-specific DNA probe assay system using the polymerase chain reaction (PCR) method. The Mt15497G→A polymorphism was detected in 3.5% (n=60) of all subjects: 2.8% (n=23) among women and 4.1% (n=37) among men. After adjusting for age and smoking, we found that body weight, body mass index, waist and hip circumferences, fat mass, fat-free mass, intra-abdominal fat and triglycerides were significantly greater in women with the A allele compared with the G allele (p=0.001–0.025). For men, waist to hip ratio was significantly greater (p=0.032), and waist circumference, intra-abdominal fat and triglycerides had a trend to be significantly greater (p=0.062–0.087) in subjects with the A allele compared with the G allele. These data suggest that the Mt15497 polymorphism may be associated with obesity-related variables and lipid metabolism.

The influence of physical activity-induced energy expenditure on the variance in body weight change among individuals during a diet intervention.

SUMMARY OBJECTIVE We investigated the relationship between the variability in body weight change among individuals and diet restriction or physical activity during a 14-week intervention. DESIGN A prospective clinical trial with a 14-week weight reduction intervention design. In total, 90 middle aged, Japanese, obese women enrolled as subjects. MEASUREMENTS The outcome variable was the change in body weight during the intervention period. Other primary variables were total energy intake, carbohydrate intake, fat intake, protein intake, total energy expenditure (TEE), and activity energy expenditure (AEE). Diet intake was assessed by 3 days, weighed dietary records and dietary recall interviews. Physical activity was assessed by a uniaxial accelerometry sensor and a diary of exercise. RESULTS Significant reductions were observed in body weight (-8.5 kg) as a result of intervention. When the subjects were assigned to three categories depending on AEE during intervention, the loss of body weight was significantly greater for subjects within the upper (-9.6 kg) AEE category than for those in the middle (-8.5 kg) or lower AEE (-7.5 kg) categories. In addition, a significant correlation (r = 0.57, p < 0.0001) was observed between a subjects AEE before and during the intervention. On the other hand, no significant correlation was observed between body weight reduction and energy intake, indicating that strict diet restriction does not always result in a large weight loss. CONCLUSION Activity energy expenditure, not only through voluntary exercise but also through spontaneous, daily, physical activities can have a positive effect on reducing body weight.