Publications (9)20.71 Total impact
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Article: Reduction in Adiposity, β-Cell Function, Insulin Sensitivity, and Cardiovascular Risk Factors: A Prospective Study among Japanese with Obesity.
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ABSTRACT: A reduction in adiposity may be associated with an improvement in insulin sensitivity and β-cell function as well as cardiovascular disease (CVD) risk factors; however, few studies have investigated these associations in a longitudinal setting. To investigate these associations over a 1-year period, we conducted an observational analysis of 196 Japanese subjects with obesity in the Saku Control Obesity Program. We investigated the relations between changes in adiposity (body mass index [BMI], waist circumference, subcutaneous fat area [SFAT], and visceral fat area [VFAT]) and changes in HbA1c, fasting plasma glucose (FPG), insulin sensitivity index (ISI), the homeostasis model assessment β cell function (HOMA-β), lipids, and blood pressure. All adiposity changes were positively associated with HbA1c and FPG changes. Reductions in BMI and VFAT were associated with HOMA-β reduction. Reductions in all adiposity measures were associated with an improvement in the ISI. Changes in most adiposity measures were positively associated with changes in blood pressure and lipid levels, except for LDL. The present findings provide additional supportive evidence indicating that a reduction in adiposity may lead to an improvement in insulin sensitivity and the reduction of CVD risk factors in obese individuals.PLoS ONE 01/2013; 8(3):e57964. · 4.09 Impact Factor -
Article: Preproghrelin gene polymorphisms in obese Japanese women: Minor homozygotes are light eaters, do not prefer protein or fat, and apparently have a poor appetite.
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ABSTRACT: Preproghrelin gene single-nucleotide polymorphisms are possible predisposing factors to obesity and other metabolic syndromes. To study the correlation between genotypes and obesity, we recruited 117 obese Japanese women (BMI, 25.0-41.1; average, 31.1). Minor homozygotes for 5 preproghrelin gene polymorphisms, namely, -1500C>G (rs3755777), -1062G>C (rs26311), -994C>T (rs26312) (promoter region), Leu72Met (rs696217) (exon 2), and +3056T>C (rs2075356) (intron 2), had high values of total and visceral fat areas, waist circumference, and BMI, indicating significant correlation of the polymorphisms with obesity and fat metabolism. Here, we studied the relationship between the genotypes and dietary tendency. Self-administered Diet History Questionnaire showed that total food intake, sugar, and dairy product intake were low in +3056C/C women. Their energy, protein, fat, and meat intake was also low. Energy balance calculation showed considerably reduced fat and protein consumption. Dietary habits were surveyed using Sakata's Questionnaire on Eating Behavior. Of the genotypes, -1062C/C women showed low scores for "motivation for eating" and "eating because of stress or something else." Thus, surprisingly, it was revealed that minor homozygotes for preproghrelin gene polymorphisms were light eaters, did not prefer fat or protein, and apparently had a poor appetite, although they were predisposed to obesity.Appetite 12/2012; · 2.59 Impact Factor -
Article: Associations of sex hormone-binding globulin and testosterone with diabetes among men and women (the Saku Diabetes study): a case control study.
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ABSTRACT: BACKGROUND: Sex hormone-binding globulin (SHBG) levels and sex hormones have been implicated in the pathogenesis of type 2 diabetes and cardiovascular diseases. As fatty liver has been suggested to be a major determinant of SHBG levels, we examined whether the associations of SHBG and testosterone with diabetes were independent of fatty liver. METHODS: We conducted a case--control study that included 300 diabetes cases (215 men and 85 women) and 300 matched controls from the Saku cohort study. Diabetes was defined by either fasting plasma glucose levels >=126 mg/dL, 2-h post-load glucose levels >=200 mg/dL after a 75 g oral glucose tolerance test, or diabetes diagnosed by physicians. We fitted conditional logistic regression models to examine the associations between SHBG and total testosterone levels with diabetes by sex. To evaluate the impact of fatty liver, we used the fatty liver index (FLI), a validated measure derived from serum triglyceride levels, body mass index (BMI), waist circumference, and gamma-glutamyltransferase levels. RESULTS: After adjusting for age, family history of diabetes, smoking, physical activity, BMI, and FLI, SHBG levels were inversely associated with diabetes among women (odds ratio [OR] comparing the highest with the lowest quartiles, 0.13 [95% confidence interval {CI}, 0.02--0.96]), but not among men. Similar patterns were observed in a subgroup analysis restricted to postmenopausal women (OR, 0.13 [95% CI, 0.02--0.96]). In contrast, testosterone levels were inversely associated with diabetes among men (OR, 0.45 [95% CI, 0.23--0.89]), but not among women. CONCLUSIONS: Our findings suggest that SHBG in women and testosterone in men may be inversely associated with diabetes.Cardiovascular Diabetology 10/2012; 11(1):130. · 3.35 Impact Factor -
Article: Dietary glycemic index and glycemic load in relation to HbA1c in Japanese obese adults: a cross-sectional analysis of the Saku Control Obesity Program.
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ABSTRACT: BACKGROUND: Dietary glycemic index or load is thought to play an important role in glucose metabolism. However, few studies have investigated the relation between glycemic index (GI) or load (GL) and glycemia in Asian populations. In this cross-sectional analysis of a randomized controlled trial, the Saku Control Obesity Program, we examined the relation between the baseline GI or GL and glycemia (HbA1c and fasting plasma glucose [FPG] levels), insulin resistance (HOMA-IR), beta-cell function (HOMA-beta), and other metabolic risk factors (lipid levels, diastolic and systolic blood pressure, and adiposity measures). METHODS: The participants were 227 obese Japanese women and men. We used multiple linear regression models and logistic regression models to adjust for potential confounding factors such as age, sex, visceral fat area, total energy intake, and physical activity levels. RESULTS: After adjustments for potential confounding factors, GI was not associated with HbA1c, but GL was positively associated with HbA1c. For increasing quartiles of GI, the adjusted mean HbA1c were 6.3%, 6.7%, 6.4%, and 6.4% (P for trend = 0.991). For increasing quartiles of GL, the adjusted mean HbA1c were 6.2%, 6.2%, 6.6%, and 6.5% (P for trend = 0.044). In addition, among participants with HbA1c >= 7.0%, 20 out of 28 (71%) had a high GL (>= median); the adjusted odds ratio for HbA1c >= 7.0% among participants with higher GL was 3.1 (95% confidence interval [CI] = 1.2 to 8.1) compared to the participants with a lower GL (<median). Further, among 16 participants with FPG >= 150 mg/dL, 13 participants (81.3%) had a higher GL; the adjusted odds ratio for FPG >= 150 mg/dL among participants with a higher GL was 8.5 (95% confidence interval = 1.7 to 43.4) compared to those with a lower GL. In contrast, GI and GL were not associated with metabolic risk factors other than glycemia. CONCLUSIONS: Our findings suggest that participants with poor glycemic control tend to have a higher GL in an obese Japanese population.Nutrition & Metabolism 09/2012; 9(1):79. · 2.88 Impact Factor -
Article: Behavioral change during weight loss program and one-year follow-up: Saku Control Obesity Program (SCOP) in Japan.
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ABSTRACT: This study evaluated effects of a behavioral approach which placed emphasis on tailored behavior counseling, diet, weight loss and weight maintenance. A one-year randomized controlled trial was conducted among 235 overweight/obese adults in Japan. The intervention group (n=119) received individual-based counseling using a behavioral approach and the changes made in the diet and physical activity were dependent on each participant as much as possible. One year later, the intervention group lost significantly more weight than the control group (-5.0 kg vs. 0.1 kg for men and -3.9 kg vs. -0.2 kg for women). Compared to the control group, the male intervention group reduced overall energy, cereals and dairy products consumption significantly, while increasing green and yellow vegetable intake, and the female intervention group significantly reduced intake of dairy products. Regarding behaviors, both male and female intervention groups increased the number of walking steps and women improved their irregular eating habits compared to those in the control groups. Behavior changes were related to weight loss; participants who maintained the action/maintenance stage or moved to later stages lost significantly more weight than participants who remained in the pre-contemplation/contemplation/preparation stages or regressed to earlier stages. After one-year follow-up, the intervention group maintained significantly lower weights, lower energy intakes and improvements in irregular eating habits. Our behavioral approach led to diet and behavior modification, weight loss and maintenance. Because modified variables differed between men and women, gender-specific approaches may be necessary.Asia Pacific Journal of Clinical Nutrition 01/2012; 21(1):22-34. · 1.13 Impact Factor -
Article: What behaviors are important for successful weight maintenance?
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ABSTRACT: Purpose. To examine behavioral factors related to successful weight maintenance. Methods. Subjects were 90 middle-aged participants who attended a weight loss program and were followed for one year. The subjects were classified into either successful weight maintainers (maintained a weight loss of 5% or more from their initial weight for one year) (SWM) or unsuccessful weight maintainers (USWM), and weight control practice, stress, obstacles, support, and self-efficacy during the program and follow-up period were compared. Results. SWM had mean loss of 12% from their initial weight during the program. They showed a greater improvement in their regularity of eating, walked more, and felt less stress regarding their increased physical activity than the USWM. During the follow-up period, significantly more SWM participants had self-efficacy (for measuring weight, practicing dietary objective, and assessing the practice and keeping records), actually kept records and measured weight more than the USWM participants. In contrast, more USWM participants felt stress about measuring weight. Conclusion. In addition to a substantial initial weight loss due to an increased amount of physical activity, having a higher self-efficacy and consistently keeping records of one's activities, as well as regularly weighing themselves, may be important for successful weight maintenance.Journal of obesity 01/2012; 2012:202037. -
Article: Relation of body composition to daily physical activity in free-living Japanese adult women.
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ABSTRACT: The objective of the present study was to investigate the relationship between the indices of body size such as BMI, fat-free mass index (FFMI, FFM/height2), fat mass index (FMI, FM/height2), and body fat percentage (%BF), and physical activities assessed by the doubly-labelled water (DLW) method and an accelerometer in free-living Japanese adult women. We conducted a cross-sectional study in 100 female subjects ranging in age from 31 to 69 years. Subjects were classified in quartiles of BMI, FFMI, FMI and %BF. Daily walking steps and the duration of light to vigorous physical activity were simultaneously assessed by an accelerometer for the same period as the DLW experiment. Only physical activity-related energy expenditure (PAEE)/FFM and PAEE/body weight (BW) decreased in the highest quartile of BMI. Physical activity level, PAEE/FFM and PAEE/BW decreased in the highest quartile of FMI and %BF, whereas they were not different among quartiles of FFMI. Daily walking steps and the duration of moderate- and vigorous-intensity physical activities decreased or tended to decrease in the highest quartile of FMI and %BF, but did not differ among quartiles of FFMI and BMI. These results clearly showed that Japanese adult women with higher fat deposition obviously had a low level of physical activities assessed by both the DLW method and accelerometry, but those with larger BMI had lower PAEE/FFM and PAEE/BW only. Our data suggest that the relationship between obesity and daily physical activities should be discussed using not only BMI but also FMI or %BF.The British journal of nutrition 05/2011; 106(7):1117-27. · 3.45 Impact Factor -
Article: Congener-specific polychlorinated biphenyls and the prevalence of diabetes in the Saku Control Obesity Program (SCOP).
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ABSTRACT: The prevalence of diabetes is increasing globally. In addition to established risk factors for diabetes, such as diet, inactivity, overweight and obesity, the involvement of persistent organic pollutants, including dioxins and polychlorinated biphenyls (PCBs), has also been suggested to be a possible, but controversial, cause of this epidemic. The present study investigated the association between blood PCB congener levels and the prevalence of diabetes among middle-aged, overweight and obese Japanese participants in the Saku Control Obesity Program. One hundred seventeen participants had their congener-specific PCB levels measured in addition to undergoing routine blood analyses at the time of a medical checkup. Prevalent diabetes was defined according to two methods: definite diabetes was defined as people with an HbA1c level ≥ 6.9% or who were taking medication for diabetes, and all diabetes was defined as people with an HbA1c level ≥ 6.5%, a fasting plasma glucose level ≥ 126 mg/dL, or a history of doctor-diagnosed diabetes. A multiple logistic regression analysis was performed to analyze the association between the PCB levels and the prevalence of diabetes, with adjustments for sex, age, body mass index and total lipids. As a result, PCB 146 and 180 were positively associated and PCB 163/164 and 170 were negatively associated with the prevalence of definite diabetes. The significance of the association of PCB 180 and 163/164 with the prevalence of diabetes persisted regardless of the definition of diabetes or adjustments for total lipids, suggesting the possibility that these parameters may modify the risk of diabetes.Endocrine Journal 05/2011; 58(7):589-96. · 2.03 Impact Factor -
Article: Obese Japanese adults with type 2 diabetes have higher basal metabolic rates than non-diabetic adults.
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ABSTRACT: Several cross-sectional studies in Pima Indians and Caucasians have indicated that obese individuals with type 2 diabetes have a higher basal metabolic rate (BMR) than healthy, obese individuals. However, no study has investigated this comparison in Japanese subjects, who are known to be susceptible to type 2 diabetes due to genetic characteristics. Thirty obese Japanese adults with pre-type 2 diabetes (n=7) or type 2 diabetes (n=13) or without diabetes (n=10) participated in this study. BMR was measured using indirect calorimetry. The relationships between residual BMR (calculated as measured BMR minus BMR adjusted for fat-free mass, fat mass, age, and sex) and biomarkers including fasting glucose, glycosylated hemoglobin (HbA(1c)), fasting insulin, homeostasis model assessment of insulin resistance (HOMA-R), triglycerides, and free fatty acids were examined using Pearson's correlation. BMR in diabetic subjects adjusted for fat-free mass, fat mass, age, and sex was 7.1% higher than in non-diabetic subjects. BMR in diabetic subjects was also significantly (p<0.05) higher than in non-diabetic subjects. There was a significant correlation between residual BMR and fasting glucose (r=0.391, p=0.032). These results indicate that in the Japanese population, obese subjects with type 2 diabetes have higher BMR compared with obese non-diabetic subjects. The fasting glucose level may contribute to these differences.Journal of Nutritional Science and Vitaminology 01/2011; 57(5):348-54. · 1.20 Impact Factor
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Institutions
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2013
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National Institute of Health and Nutrition
Tokyo, Tokyo-to, Japan
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