Kayo Takahashi

Daily walking reduces visceral adipose tissue areas and improves insulin resistance in Japanese obese subjects

OBJECTIVE It is known that the accumulation of abdominal fat is one of the risk factors for atherosclerosis. Although exercise is commonly prescribed to reduce body weight, the efficacy of low intensity exercise for the reduction of abdominal visceral adipose tissue remains to be investigated. RESEARCH DESIGN AND METHODS Thirty one obese Japanese males (body mass index (BMI) > or = 25) ranging in age from 32 to 59, participated in a 1-year follow up study and they were instructed to have a modest increase in daily activity and record their daily walking. Before and after exercise prescription, body composition, blood pressure, physical fitness i.e. aerobic exercise level, muscle strength and flexibility were recorded. Insulin resistance was evaluated using a homeostasis model assessment, the HOMA index. RESULTS HOMA index, parameters of body composition, blood pressure, triglyceride and HDL cholesterol were significantly improved. The aerobic exercise level, leg strength, weight-bearing index (leg strength/body weight) and the steps taken per day were significantly increased. By stepwise multiple regression analysis, Delta visceral adipose tissue area was the major determinant for Delta HOMA index. (Delta HOMA index=-0.386+0.016 Delta visceral adipose tissue area, r2=0.267, P<0.01). Exercise capacity and calorie intake were not significantly related to Delta visceral adipose tissue area, while Delta steps per day was significantly correlated with Delta visceral adipose tissue area (Delta visceral adipose tissue area=-21.363-0.004 Delta steps per day, r2=0.184, P=0.0326). CONCLUSIONS Taken together, intra-abdominal visceral adipose tissue is critically involved in insulin resistance and daily walking rather than improvement of exercise capacity correlated with the reduction of visceral adipose tissue in obese Japanese males.

Re-evaluation of exercise prescription for Japanese type 2 diabetic patients by ventilatory threshold

Prescription of aerobic exercise for Type 2 diabetes mellitus (Type 2 DM) in clinical practice is frequently based on exercise intensity at maximum heart rate (60<HR(max)<79%), heart rate reserve (50<HR(reserve)<74%), and rating of perceived exertion (12<RPE<13). We examined these parameters in Japanese males with Type 2 DM at ventilatory threshold (VT) to investigate the exercise capacity of Type 2 DM patients and re-evaluate the exercise prescription. Fifty-six Japanese Type 2 DM males without autonomic neuropathy [age, 53.5+/-7.7 years; body mass index (BMI), 23.7+/-3.6 kg/m(2)] were enrolled and compared with 56 age- and BMI-matched healthy Japanese males. VT was determined breath by breath during exercise test using a ramp protocol and rates of oxygen consumption (VO(2)), work rate (WR), HR, DeltaHR, %HR(max), %HR(reserve), and RPE were measured at VT. Type 2 DM patients had significantly lower VO(2) (3.6+/-0.4 metabolic equivalents (METs)) and WR (62+/-14 W) than controls (VO(2), 3.9+/-0.6 METs; WR, 74+/-13 W). %HR(reserve), (32.6+/-7.7%) was also significantly lower compared with controls (37.6+/-8.3%), while %HR(max), was not different. RPE was also similar in diabetics (12.4+/-1.5) and controls (12.9+/-1.2), however, it was significantly lower in diabetic patients aged 60-69 years (11.8+/-2.0) and those with distal symmetric sensory neuropathy (12.2+/-1.0). Our results indicate reduced exercise capacity in Japanese Type 2 DM males and the exercise intensity of 60%HR(max), 30%HR(reserve), and RPE 12 is recommended in elderly diabetics and those with diabetic sensory neuropathy.

Relationship between reduced serum IGF-I levels and accumulation of visceral fat in Japanese men.

OBJECTIVE: To investigate whether the changes in IGF-I concentrations after weight reduction in Japanese overweight men are associated with changes in visceral and subcutaneous fat.DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education.SUBJECTS: One-hundred and twelve Japanese overweight men aged 30–59 y (body mass index (BMI) 28.4±2.5 kg/m2) and 33 normal-weight men aged 30–39 y (BMI 22.1±1.5 kg/m2) at baseline. From the participants, 56 randomly selected overweight men (BMI 28.8±2.8) were further enrolled into a 1 y exercise program.MEASUREMENTS: Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, metabolic parameters and hormones including insulin, leptin and IGF-I at baseline and after 1 y.RESULTS: In 112 overweight subjects at baseline, insulin (10.5±5.0 µU/ml) and leptin (6.4±3.7 ng/ml) significantly correlated with both V (r=0.260, P=0.0073; r=0.410, P<0.0001) and S areas (r=0.377, P<0.0001; r=0.613, P<0.0001), respectively. IGF-I (156.8±48.7 µU/ml) significantly and negatively correlated with V area (r=−0.242, P=0.0125) and age (r=−0.192, P=0.0480). In normal-weight men aged 30–39 y (n=33) and age-matched subjects (n=30) selected from the 112 overweight men, the serum IGF-I further tightly correlated with V area (r=−0.467, P<0.0001). Visceral fat area and age were independently related to serum IGF-I levels by multiple regression analysis. By intervention with exercise education, 56 overweight subjects showed an increase in daily steps (6224±2781 to 7898±4141 steps/day) and reduction of BMI (28.8±2.8 to 27.7±2.9). ΔIGF-I significantly correlated with ΔV area (r=−0.432, P=0.0009) but not with ΔS area or ΔBMI.CONCLUSION: The present study indicated a negative correlation between IGF-I levels and visceral fat at baseline as well as an association between the reduction in visceral fat and increase in IGF-I levels after an exercise intervention.

Changes in serum leptin concentrations in overweight Japanese men after exercise

Aim:  To investigate the link between serum leptin concentrations and exercise.

Effects of cytokines on human basophil chemotaxis

Basophil chemotactic activity (BCA) of eight recombinant human (rh) cytokines was examined. Highly purified basophils were obtained by Percoll discontinuous gradients, followed by negative selection using flow cytometry. Then BCA was measured by means of modified Boyden chamber method. Both interleukin (IL)‐3 and granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) had much more potent BCA than complement C5a, leukotriene B4 and platelet activating factor, well known as granulocyte chemotactic factors. Chemotaxis rather than chemokinesis was shown in chequerboard analysis of basophil migration induced by IL‐3 and GM‐CSF. Relatively high concentrations of IL‐5 also induced basophil migration, although predominantly chemokinetic. IL‐8 had apparent BCA, which was not so high as that of C5a. In contrast, IL‐2, IL‐4, interferon(IFN)‐γ and granulocyte colony‐stimulating factor (G‐CSF) had no significant BCA. These findings suggest that IL‐3, IL‐5, GM‐CSF and, perhaps, IL‐8 have an effect on basophil migration as well as modulation of basophil mediator release and may provide some insight into the basophil accumulation observed in late‐phase allergic responses.

Effect of sports activity on bone mineral density in wheelchair athletes

The present study carried out a measurement of body composition and a nutrition survey, targeting 28 male wheelchair athletes and comparing them with 25 male physically able healthy athletes as the controls. The DXA method was used to measure bone mineral density (BMD), percentage of body fat (% body fat), and lean body mass (LBM). Possible factors affecting the BMD of the wheelchair athletes with spinal injuries were analyzed including age, body part, type of sport, area of injury, length of injury, and the length of time it took before restarting sports activity after injury. BMD in the arms, body trunk, legs, and entire body was measured. There were no significant differences in the BMD of the wheelchair athletes by age group (from 20 to 29, from 30 to 39, and 40 years and older), by sports (basketball, track and field, and tennis), and by area of injury (high and low paraplegia). BMD in the legs (r = −0.549, P < 0.01), body trunk (r = −0.414, P < 0.05), and entire body (r = −0.452, P < 0.05) of the wheelchair athletes was negatively correlated with the period since injury; however, no such a relationship was observed in the arms. In addition, the multiple regression analysis for BMD of each body region showed that the earlier the wheelchair athletes restarted sports after injury, the higher values the BMD of legs (r = −0.467, P < 0.05), body trunk (r = −0.469, P < 0.05), and entire body (r = −0.488, P < 0.05), independent of age and sports. The leg BMD of the wheelchair athletes was lower than that of the physically able athletes, with a BMD 76.5% of the controls. The present study suggests that restarting sports activity in a timely manner after treatment and rehabilitation for the injury is useful in preventing loss of BMD in wheelchair athletes and ultimately improving their quality of life.

Daily exercise lowers blood pressure and reduces visceral adipose tissue areas in overweight Japanese men

OBJECTIVE To investigate the link between a reduction in blood pressure (BP) and daily exercise. DESIGN Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS 43 overweight Japanese men aged 32-59 years (BMI, 29.0+/-2.3 kg/m2) at baseline. Among the participants, a randomly selected 23 overweight men (BMI, 28.5+/-1.7) were further enrolled into the 10 months exercise program. MEASUREMENTS BP was measured every week and steps per day were also recorded every day throughout the observation period. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical level, at before, 5 months and after intervention. Anthropometric parameters were also measured at same point. Aerobic exercise level, muscle strength, flexibility and calorie intake and insulin resistance (HOMA index) were investigated at before and after the study. RESULTS In a cross sectional analysis, systolic BP (SBP) and diastolic BP (DBP) were significantly correlated with body composition. In a second longitudinal analysis, SBP was significantly reduced at 2 months and DBP was also reduced at 3 months, and almost maintained until the end of the observation period. Increasing daily walking was observed in 3 months and maintained until 10 months. Body composition, aerobic exercise level, muscle strength, flexibility and insulin resistance were significantly improved. There was positive correlation between DeltaDBP and Deltavisceral fat area (1-5, 5-10, 1-10 months). By stepwise multiple regression analysis, only Deltavisceral fat area was independently related to DeltaDBP at a significant level (1-10 months: DeltaDBP=-0.608+0.105Deltavisceral fat area, r2=0.227, P=0.0334). CONCLUSION The present study indicated daily exercise lowers BP and visceral fat area is the critical factor for BP change.

Serum bFGF levels are reduced in Japanese overweight men and restored by a 6-month exercise education.

OBJECTIVE: To investigate whether the changes in vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) concentrations before and after weight reduction in Japanese overweight men are associated with changes in body mass index (BMI), visceral, subcutaneous fat, VO2 and work rate (WR) at ventilatory threshold (VT).DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education.SUBJECTS: In total, 30 Japanese overweight men (BMI, 29.0±2.2 kg/m2) and 31 normal-weight men (BMI, 22.5±1.6 kg/m2) at baseline were enrolled: 30 overweight men (BMI, 29.0±2.2 kg/m2) were further enrolled into a 6-month exercise program.MEASUREMENTS: Fat distribution evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, angiogenic peptides including VEGF and bFGF, exercise tests at baseline and after 6 months.RESULTS: In normal-weight and overweight subjects at baseline, VEGF positively correlated with S area (r=0.350, P=0.007) but not with V area. In contrast, bFGF negatively correlated with BMI (r=−0.619, P<0.001), S (r=−0.457, P<0.001) and V areas (r=−0.466, P<0.001). By intervention with exercise education, 30 overweight subjects showed reduction in BMI (29.0±2.2 to 28.0±2.0, P<0.001), V and S areas, increase in VO2 and WR at VT, increase in bFGF (9.21±5.82–21.2±7.04 ng/ml, P<0.001), and no change in VEGF (1.45±0.72–1.88±0.52 ng/ml, P=0.016). The stepwise multiple regression analysis revealed that ΔBMI (β=−6.052) and ΔVO2 (β=2.806) were independently related to ΔbFGF (P<0.001) and all other variables including ΔS area, and ΔV area, and ΔWR did not enter the equation at significant levels.CONCLUSION: The present study indicated a negative correlation between serum bFGF levels and BMI at baseline as well as an association of ΔBMI and ΔVO2 with ΔbFGF after exercise intervention. The exercise-induced elevation of bFGF may be beneficial in the prevention of the atherosclerosis in overweight subjects.

Ultrasound assessment of tibial cortical bone acquisition in Japanese children and adolescents

Abstract. The purpose of the present study was to evaluate the normal process of cortical bone acquisition during childhood and adolescence, and the relationship between speed of sound (SOS), measured by the Sound Scan 2000 system, and linear growth. A total of 1689 healthy Japanese children and adolescents (862 males and 827 females, aged 7–19 years) were enrolled in the study. SOS (m/s) was measured at the right tibial midshaft and the standard SOS values in the children and adolescents were generated. Various growth parameters were also measured. SOS of tibia increased significantly with age in both males and females (P < 0.001 each). In both sexes, a spurt in SOS was noted 1 year after the standard age at which Japanese peak height velocity (PHV; cm/year) occurs, and SOS increased markedly after the age at which the length of tibia reached a maximum. Multiple regression equations for SOS were generated as a function of various growth parameters; for males, SOS = 3047 + 6.2 × height (cm) + 2.1 × weight (kg) − 9.8 × length of tibia (cm) (R2 = 0.50; P < 0.001) and for females, SOS = 2713 + 10.3 × height (cm) + 1.8 × weight (kg) − 15.5 × length of tibia (cm) (R2 = 0.49; P < 0.001). In both sexes, SOS correlated positively with body height and weight, but negatively with length of tibia. Our results indicate that SOS is quite useful for evaluating cortical bone status in children and adolescents; the results of these measurements may provide an explanation for the relative weakness of the mechanical properties of the bone during childhood and adolescence.

Differences in response to anti‐IgE and to anti‐IgG in basophils from patients with bronchial asthma

Peripheral blood basophils of thirty‐eight patients with bronchial asthma were examined for their reactivity to anti‐IgE and anti‐IgG antisera. Basophils of patients with serum IgE levels of more than 1001 i.u./ml reacted strongly to anti‐IgE. Basophils of patients with serum IgE levels of less than 100 i.u./ml had a tendency to react more strongly to anti‐IgG. An index (basophil ratio) was devised to compare the patient basophil reactivity to anti‐IgE and anti‐IgG. This basophil ratio was lower (IgE dominant) in the atopic cases which usually exhibited a high serum IgE level. Most cases with low serum IgE exhibited a high basophil ratio (IgG dominant). The basophils of seven intractable patients reacted more strongly to anti‐IgG than to anti‐IgE regardless of the serum IgE level.