Three percent weight reduction is the minimum requirement to improve health hazards in obese and overweight people in Japan.

OBJECTIVE: Adequate goal-setting is important in health counselling and treatment for obesity and overweight. We tried to determine the minimum weight reduction required for improvement of obesity-related risk factors and conditions in obese and overweight Japanese people, using a nationwide intervention programme database. METHODS: Japanese men and women (n=3480; mean age±standard deviation [SD], 48.3±5.9 years; mean body mass index±SD, 27.7±2.5kgm(-2)) with "Obesity Disease" or "Metabolic Syndrome" participated in a 6-month lifestyle modification programme (specific health guidance) and underwent follow-up for 6 months thereafter. The relationship between percent weight reduction and changes in 11 parameters of obesity-related diseases were examined. RESULTS: Significant weight reduction was observed 6 months after the beginning of the programme, and it was maintained for 1 year. Concomitant improvements in parameters for obesity-related diseases were also observed. One-third of the subjects reduced their body weight by ≥3%. In the group exhibiting 1% to <3% weight reduction, plasma triglycerides (TG), low-density lipoprotein cholesterol (LDL-C), haemoglobin A1c (HbA1c), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and γ-glutamyl transpeptidase (γ-GTP) decreased significantly, and high-density lipoprotein cholesterol (HDL-C) increased significantly compared to the control group (±1% weight change group). In addition to the improvements of these 7 parameters (out of 11), significant reductions in systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (FPG) and uric acid (UA) (total 11 of 11 parameters) were observed in the group with 3% to <5% weight reduction. In the group with ≥5% weight reduction, the same 11 parameters also improved as those in the group with 3% to <5% weight reduction. CONCLUSION: The 6-month lifestyle modification programme induced significant weight reduction and significant improvement of parameters of obesity-related diseases. All the measured obesity-related parameters were significantly improved in groups with 3% to <5% and ≥5% weight reduction. Based on these findings, the minimum weight reduction required for improvement of obesity-related risk factors or conditions is 3% in obese and overweight (by WHO classification) Japanese people.

Circulating adiponectin levels are associated with peak oxygen uptake in Japanese.

OBJECTIVE: The aim of this study was to investigate the link between circulating adiponectin levels and peak oxygen uptake and/or physical activity in Japanese. METHODS: A total of 528 subjects (188 men and 340 women) were enrolled in this cross-sectional study. Circulating adiponectin levels, physical activity measured by tri-axial accelerometers, peak oxygen uptake and metabolic risk parameters were evaluated. We also assessed anthropometric factors, blood pressure, blood examinations and energy intake. RESULTS: Circulating adiponectin levels were 6.7 ± 3.0 µg/mL in men and 11.0 ± 4.9 µg/mL in women. Circulating adiponectin levels were positively correlated with physical fitness after adjusting for age, physical activity evaluated by Σ [metabolic equivalents × h per week (METs h/w)], cigarette smoking habit and energy intake in both sexes. However, these associations were attenuated further after adjusting for body mass index including other confounding factors, especially in men. However, circulating adiponectin levels were not associated with physical activity in either sex. CONCLUSION: Circulating adiponectin levels were associated with peak oxygen uptake rather than physical activity.

Lifestyle modification is associated with improving estimated glomerular filtration rate (eGFR) and proteinuria in Japanese with proteinuria.

The link between lifestyle modification and changes in both proteinuria and estimated glomerular filtration rates (eGFRs) was evaluated in Japanese subjects with proteinuria who were not taking medications. We used data from 51 men (35.8±10.0 years) and 74 women (38.0±11.0 years) with proteinuria at baseline and a 1-year follow up. eGFR was defined by a new equation developed specifically for Japanese subjects. Subjects were given advice for dietary and lifestyle improvement at the initial appointment. At the 1-year follow up, eGFR was increased in both sexes, but not at significant levels. (men:p＝0.7709, women:p＝0.2180). Proteinuria was also improved in many subjects. A decrease in proteinuria may be associated with improving eGFR in Japanese.

Serum vaspin levels are associated with physical activity or physical fitness in Japanese: a pilot study.

AIM: To investigate the link between serum vaspin levels and physical activity and/or physical fitness in Japanese. METHODS: A total of 156 subjects (81 men and 75 women) was enrolled in this cross-sectional study. Serum vaspin levels, physical activity by uniaxial accelerometers, peak oxygen uptake, and metabolic risk parameters were evaluated. We also assessed anthropometric and body composition parameters. RESULTS: Serum vaspin levels were over the level of 10 ng/mL in 15 subjects (9.6 %: Vaspin High group). In Vaspin Low group (<5 ng/mL: 74 men and 67 women), serum vaspin levels were 0.12 ± 0.18 ng/mL in men and 0.39 ± 0.70 ng/mL in women. Peak oxygen uptake was significantly and positively correlated with serum vaspin levels even after adjusting for age, physical activity evaluated by Σ[metabolic equivalents × h per week (METs[Symbol: see text]h/w)], BMI, and other confounding factors in men. In turn, physical activity was significantly and positively correlated with serum vaspin levels even after adjusting for confounding factors in women. CONCLUSION: Serum vaspin levels were closely associated with physical fitness in men and physical activity in women independent of body composition in this Japanese cohort.

Serum interleukin-18 levels are associated with physical activity in Japanese men.

OBJECTIVE: To investigate the link between serum interleukin-18 (IL-18) levels and physical activity in Japanese men. METHODS: A total of 81 men (45.7±17.6 years old) was enrolled in this cross-sectional investigation study. We assessed anthropometric and body composition parameters. Serum IL-18 levels, physical activity by uniaxial accelerometers, peak oxygen uptake and metabolic risk parameters were also evaluated. RESULTS: Serum IL-18 levels were 179.4±84.7 pg/mL. Physical activity evaluated by Σ[metabolic equivalents × h per week (METs⋅h/w)]was significantly and negatively correlated with serum IL-18 levels (r = -0.252, p = 0.0235). These associations remained even after adjusting for age, peak oxygen uptake and other confounding factors. CONCLUSION: Serum IL-18 levels were closely associated with physical activity independent of peak oxygen uptake in Japanese men.

Does cardiorespiratory fitness modify the association between birth weight and insulin resistance in adult life?

OBJECTIVE: Lower birth weight is associated with higher insulin resistance in later life. The aim of this study was to determine whether cardiorespiratory fitness modifies the association of birth weight with insulin resistance in adults. METHODS: The subjects were 379 Japanese individuals (137 males, 242 females) aged 20-64 years born after 1943. Insulin resistance was assessed using a homeostasis model assessment of insulin resistance (HOMA-IR), which is calculated from fasting blood glucose and insulin levels. Cardiorespiratory fitness (maximal oxygen uptake, VO2max) was assessed by a maximal graded exercise test on a cycle ergometer. Birth weight was reported according to the Maternal and Child Health Handbook records or the subject's or his/her mother's memory. RESULTS: The multiple linear regression analysis revealed that birth weight was inversely associated with HOMA-IR (ß = -0.141, p = 0.003), even after adjustment for gender, age, current body mass index, mean blood pressure, triglycerides, HDL cholesterol, and smoking status. Further adjustments for VO2max made little difference in the relationship between birth weight and HOMA-IR (ß = -0.148, p = 0.001), although VO2max (ß = -0.376, p<0.001) was a stronger predictor of HOMA-IR than birth weight. CONCLUSIONS: The results showed that the association of lower birth weight with higher insulin resistance was little modified by cardiorespiratory fitness in adult life. However, cardiorespiratory fitness was found to be a stronger predictor of insulin resistance than was birth weight, suggesting that increasing cardiorespiratory fitness may have a much more important role in preventing insulin resistance than an individual's low birth weight.

Relationship between cigarette smoking and muscle strength in Japanese men.

OBJECTIVES: To investigate the link between cigarette smoking and muscle strength in Japanese men. METHODS: We used data on 4249 Japanese men, aged 43.3±13.9 years, in this cross-sectional investigation study. Grip strength and leg strength were measured as indicators of overall muscle strength. Meanwhile, subjects' cigarette smoking habits were recorded by trained medical staff. The effect of cigarette smoking on muscle strength was evaluated. RESULTS: A total of 1618 men (38.1%) were smokers and 1481 men (34.9%) exercised regularly. Significant differences in muscle strength were noted between men with and without a Brinkman index of 400 or greater, after adjusting for age. After adjusting for age, height, body weight and exercise habits, associations between the Brinkman index and leg strength and the ratio of leg strength to body weight were attenuated. CONCLUSIONS: Cigarette smoking might be negatively associated with muscle strength, especially grip strength in Japanese men.

Evaluation of anthropometric parameters and physical fitness in elderly Japanese.

OBJECTIVES: We evaluated anthropometric parameters and physical fitness in elderly Japanese. METHODS: A total of 2,106 elderly Japanese (749 men and 1,357 women), aged 60-79 years, were enrolled in a cross-sectional investigation study. Anthropometric parameters and physical fitness, i.e., muscle strength and flexibility, were measured. Of the 2,106 subjects, 569 subjects (302 men and 267 women) were further evaluated for aerobic exercise level, using the ventilatory threshold (VT). RESULTS: Muscle strength in subjects in their 70s was significantly lower than that in subjects in their 60s in both sexes. Two hundred and twenty-nine men (30.6%) and 540 women (39.8%) were taking no medications. In men, anthropometric parameters were significantly lower and muscle strength, flexibility, and work rate at VT were significantly higher in subjects without medications than these values in subjects with medications. In women, body weight, body mass index (BMI), and abdominal circumference were significantly lower, and muscle strength was significantly higher in subjects without medications than these values in subjects with medications. CONCLUSION: This mean value may provide a useful database for evaluating anthropometric parameters and physical fitness in elderly Japanese subjects.

Decreasing abdominal circumference is associated with improving estimated glomerular filtration rate (eGFR) with lifestyle modification in Japanese men: a pilot study.

The link between changes in a subject's metabolic syndrome components and his estimated glomerular filtration rate (eGFR) was evaluated in healthy Japanese men. We used data from 120 Japanese men (45.5 ± 8.4 years) with a 1-year follow up. eGFR was defined by a new equation developed for Japan. There were no significant differences in eGFR between men with and without metabolic syndrome components at baseline. Subjects were given advice for dietary and lifestyle improvement. At the 1-year follow up, almost all metabolic syndrome components were significantly improved. However, eGFR was significantly decreased. The changes in eGFR were weakly correlated with abdominal circumference (r＝-0.232, p＝0.0106). A decrease in abdominal circumference may be associated with improving eGFR in Japanese men.

The relation between estimated glomerular filtration rate and proteinuria in Okayama Prefecture, Japan.

OBJECTIVE: We investigated the link between renal function as evaluated by estimated glomerular filtration rate (eGFR) and proteinuria in Okayama Prefecture, Japan. SUBJECTS AND METHODS: A total of 11030 Japanese subjects, aged between 20 and 79 years, were recruited in a cross-sectional clinical investigation study. eGFR was calculated using serum creatinine, age, and sex. Proteinuria was measured by using urine strip devices. RESULTS: Age-related variations in eGFR were noted. Two hundred sixteen men (6.2%) and 316 women (4.2%) were diagnosed with trace positive (±) and 140 men (4.0%) and 130 women (1.7%) were diagnosed with positive (+≤) proteinuria. eGFR in subjects with +≤ proteinuria was significantly lower than that in subjects without proteinuria, in both sexes. CONCLUSION: The present study indicates that proteinuria might be an important marker in the etiology of lower eGFR in Okayama Prefecture, Japan.

Relation between cigarette smoking and ventilatory threshold in the Japanese.

The link between cigarette smoking and ventilatory threshold (VT) was investigated. We used data for 407 men and 418 women not taking medication. Habits of cigarette smoking were obtained through interviews by well-trained staff. The influence of cigarette smoking on oxygen uptake, work rate, and heart rate at VT was evaluated. Oxygen uptake at VT in women and work rate at VT in men with cigarette smoking were significantly lower than in subjects without cigarette smoking after adjusting for age. The differences of parameters at VT did not reach significant levels after adjusting for age and exercise habits in both sexes. However, in women without exercise habits, there was significant difference of oxygen uptake at VT between women with and without cigarette smoking after adjusting for age [cigarette smoking (+): 11.5 ± 1.8 ml/kg/min, cigarette smoking (-): 12.4 ± 2.1 ml/kg/min, p = 0.0006]. The number of cigarettes smoked per day and the Brinkman Index were not clearly correlated with oxygen uptake at VT. A combination of promoting exercise habits and prohibiting cigarette smoking might be recommended for improving the aerobic exercise level, especially in women.

Decreasing systolic blood pressure is associated with improving estimated glomerular filtration rate (eGFR) with lifestyle modification in Japanese healthy women.

The link between changes in a subject's metabolic syndrome components and her estimated glomerular filtration rate (eGFR) was evaluated in healthy Japanese women. We used data for 53 Japanese women (46.0±10.9 years) with a 1-year follow up. eGFR was defined by a new equation developed for Japan. There were no significant relationships between eGFR and clinical parameters at baseline. Subjects were given advice for dietary and lifestyle improvement. At the 1-year follow up, eGFR was significantly increased. In addition, changes in eGFR were weakly correlated with systolic blood pressure(r=-0.306, p=0.0260). A decrease in systolic blood pressure may be associated with improving eGFR in Japanese women.

Relationship between estimated glomerular filtration rate (eGFR) and metabolic syndrome in Japanese.

We investigated the link between renal function as evaluated by estimated glomerular filtration rate (eGFR) and metabolic syndrome in Japanese. A total of 11,711 Japanese subjects, aged 20-79 years, were recruited in a cross-sectional clinical investigation. From this group, we further investigated the data on 1,576 subjects. eGFR was calculated using serum creatinine (Cr), age and sex. The diagnosis of metabolic syndrome was based on the Japanese criteria. In the first analysis, 288 men (7.8%) and 498 women (6.2%) were diagnosed with reduced eGFR (<60ml/min). eGFR was not correlated with anthropometric, body composition parameters in either sex. In the second analysis, in subjects without medications, 132 men (20.8%) and 15 women (1.6%) were diagnosed with metabolic syndrome. eGFR was lower in men with abdominal obesity and in women with hypertension was than in those without. Among Japanese not taking medications, lower eGFR may be a characteristic of men with abdominal obesity and of women with hypertension.

Relation between the estimated glomerular filtration rate and pulse wave velocity in Japanese.

OBJECTIVE: We investigated the link between renal function as evaluated by estimated glomerular filtration rate (eGFR) and pulse wave velocity (PWV) in Japanese without medications. METHODS: A total of 1,244 Japanese subjects, aged 20-79 years, were recruited in a cross-sectional clinical investigation study. They received no medications. eGFR was calculated using serum creatinine (Cr), age and sex. Peripheral arterial stiffness was evaluated by brachial-ankle PWV (baPWV). RESULTS: eGFR and baPWV were significantly correlated with age. eGFR was negatively correlated with baPWV (men: r=-0.308, p<0.0001, women: r=-0.293, p<0.0001). Twenty-six men (5.6%) and 35 women (4.5%) were diagnosed as reduced eGFR (eGFR <60 mL/min/1.73 m(2)). We compared clinical parameters between subjects with reduced eGFR (Group R) and without such reduction (Group N). baPWV in Group R was significantly higher than that in Group N even after adjusting for age. In women, systolic blood pressure in Group R was also significantly higher than that in Group N. CONCLUSION: eGFR was closely associated with peripheral arterial stiffness in Japanese.

Changes in metabolic syndrome and its components with lifestyle modification in Japanese men.

OBJECTIVE: Changes in metabolic syndrome and its components with lifestyle modification were evaluated in Japanese men. METHODS: We used data for 160 Japanese men (45.6+/-8.8 years) with a 1-year follow up. Anthropometric, blood examination and blood pressure measurements were evaluated. Metabolic syndrome was defined by using a criterion in Japan. All subjects were given instructions by well-trained medical staff on how to change their lifestyle. RESULTS: With a 1-year follow-up, anthropometric parameters, blood pressure (BP), triglyceride and HDL cholesterol were significantly improved and the prevalence of metabolic syndrome was significantly reduced. The number of subjects with abdominal obesity at baseline and at follow-up was higher (81 men) than that of subjects with other components at baseline and at follow-up. Parameters at baseline were significantly correlated with changes in parameters for one year. With lifestyle modification, the level of 163 mmHg in systolic BP (SBP), 115 mmHg in diastolic BP (DBP), 226 mg/dL in triglyceride and 33 mg/dL in HDL cholesterol at baseline was estimated to improve to the level without medications with a 1-year follow up. CONCLUSION: Lifestyle modification is useful for improving metabolic syndrome and its components. However, items of metabolic syndrome were improved, even when the abdominal circumference was greater than the normal value for Japanese men.

Evaluation of ventilatory threshold and its relation to exercise habits among Japanese.

OBJECTIVE: The aim of this study was to evaluate aerobic exercise levels, expressed in terms of ventilatory threshold (VT), in a Japanese population and explore the relationship between VT and exercise habits in this population. METHODS: This was a cross-sectional study in which data collected from 547 men and 524 women aged 20-69 years and not on medications, were used to assess exercise habits and parameters at VT, namely, oxygen uptake, work rate, and heart rate. RESULTS: Age-related changes in parameters at VT were noted. Of the participants, 205 men (37.5%) and 142 women (27.1%) had exercise habits. Oxygen uptake and work rate at VT in subjects with exercise habits were significantly higher than those without exercise habits after age had been adjusted for in both sexes. Anthropometric parameters were significantly correlated with oxygen uptake at VT, and the highest correlation coefficient rate was found between oxygen uptake at VT and body fat percentage (men r = -0.589, women r = -0.631). CONCLUSION: The mean values determined here may provide a useful database for evaluating VT in Japanese adult subjects.

Evaluation of muscle strength and its relation to exercise habits in Japanese.

The aim of this study was to explore muscle strength and its relation to exercise habits in Japanese. We used data from 3,018 men and 6,881 women aged 20-69 years and not using medications in a cross-sectional study. Exercise habits and muscle strength, i.e. grip strength and leg strength, were measured. Age-related changes in muscle strength were noted. Exercise habits were found in 984 men (32.6%) and 1,664 women (24.2%). For subjects of both sexes over 50 years, grip strength was significantly decreased with age. However, the ratio of leg strength to body weight significantly decreased with age as early as 30 years in men and 40 years in women. Grip strength, leg strength and the ratio of leg strength to body weight in subjects with exercise habits were significantly higher than those without exercise habits after adjusting for age in both sexes. This standard mean value may provide a useful database for evaluating muscle strength in Japanese adult subjects.

Comparison of serum uric acid levels between Japanese with and without metabolic syndrome.

OBJECTIVE: The link between uric acid levels and metabolic syndrome was investigated. METHODS: We used data for 997 men and 1290 women. Metabolic syndrome was defined by a new criterion in Japan and uric acid was measured. RESULTS: Subjects who did not drink alcohol were evaluated. Uric acid was significantly higher in subjects with metabolic syndrome compared with subjects without the syndrome in both sexes. The presence of abdominal obesity and dyslipidemia in men and abdominal obesity in women revealed positive impacts on uric acid levels. CONCLUSION: High serum uric acid may be often associated with metabolic syndrome in Japanese people, which accelerates the development of cardiovascular disease from metabolic syndrome.

Reducing waist circumference by at least 3 cm is recommended for improving metabolic syndrome in obese Japanese men.

OBJECTIVE: We investigated the link between a reduction in waist circumference and metabolic syndrome. METHODS: 105 obese Japanese men were enrolled in this study with a 1-year follow-up. Anthropometric and body composition parameters, i.e. height, body weight, body fat percentage, waist circumference and hip circumference, blood pressure, triglyceride, HDL cholesterol and blood sugar, were evaluated. Metabolic syndrome was diagnosed using criteria developed in Japan. RESULTS: After a 1-year follow-up, the parameters of metabolic syndrome were significantly improved. The prevalence of metabolic syndrome was significantly reduced in subjects with at least 3 cm of waist circumference reduction (Group R). However, in subjects without such reduction (Group C), the prevalence of metabolic syndrome was similar to baseline levels. The prevalence of abdominal obesity, hypertension and dyslipidemia was also significantly reduced in Group R. In addition, there were remarkable differences of delta triglyceride (delta represents positive changes in parameters) and delta HDL cholesterol between Group R and Group C. CONCLUSION: At least 3 cm of waist circumference reduction may be beneficial for improving metabolic syndrome in obese Japanese men.

Linkage between oxygen uptake at ventilatory threshold and muscle strength in subjects with and without metabolic syndrome.

We evaluated the linkage between oxygen uptake at the ventilatory threshold (VT) and muscle strength in subjects with and without metabolic syndrome. We used data of 226 Japanese men with metabolic syndrome and 265 Japanese men without the syndrome. Metabolic syndrome has recently been defined by a new criterion in Japan. Oxygen uptake at VT and muscle strength, i.e. grip strength and leg strength were measured. Oxygen uptake at VT and muscle strength/body weight were found to be significantly lower in subjects with metabolic syndrome than in those without the syndrome. However, the differences did not reach significant levels after adjusting for leg strength/body weight or oxygen uptake at VT. A combination of aerobic exercise and resistance training might be considered for preventing and improving metabolic syndrome.