Biomedical subjects

K Chikada

Publications and source records attributed to K Chikada.

13 recordsLinked to original sources

PubMed1995

Daily walking combined with diet therapy is a useful means for obese NIDDM patients not only to reduce body weight but also to improve insulin sensitivity.

OBJECTIVE: To evaluate the effects of walking combined with diet therapy (1,000-1,600 kcal/day) on insulin sensitivity in obese non-insulin-dependent diabetes mellitus (NIDDM) patients. RESEARCH DESIGN AND METHODS: Subjects were divided into two groups: 10 patients were managed by diet alone (group D), and 14 patients were placed in the diet and exercise group (group DE). Group DE was instructed to walk at least 10,000 steps/day on a flat field as monitored by pedometer (19,200 +/- 2,100 steps/day), and group D was told to maintain a normal daily routine (4,500 +/- 290 steps/day). A glucose clamp procedure at an insulin infusion rate of 40 microU.min-2.min-1 was performed before and after the 6- to 8-week training program. Mean serum insulin concentrations ranged from 720 to 790 pmol/l. RESULTS: While body weight (BW) in groups D and DE decreased significantly (P < 0.01) during the study, the amount of BW reduction in group DE was greater than that in group D (7.8 +/- 0.8 vs. 4.2 +/- 0.5 kg, P < 0.01). After training, glucose infusion rate (GIR) and metabolic clearance rate (MCR) in group D did not significantly increase; however, GIR and MCR increased significantly in group DE, from 17.21 +/- 1.11 to 26.09 +/- 1.11 mumol.kg-1.min-1 (P < 0.001) and from 3.0 +/- 0.3 to 5.3 +/- 0.4 ml.kg-1.min-1 (P < 0.001), respectively. The analysis of variance showed significant effects of exercise (time x exercise, P = 0.0005) for the improvement of MCR. Significant correlations were also observed between delta MCR and average steps per day (r = 0.7257, P < 0.005) in group DE. CONCLUSIONS: Walking, which can be safely performed and easily incorporated into daily life, can be recommended as an adjunct therapy to diet treatment in obese NIDDM patients, not only for BW reduction, but also for improvement of insulin sensitivity.

Adult↗

PubMed1992

Metabolic effects of proglycosyn.

Proglycosyn, a phenylacyl imidazolium compound that lowers blood glucose levels, was demonstrated previously to promote hepatic glycogen synthesis, stabilize hepatic glycogen stores, activate glycogen synthase, inactivate glycogen phosphorylase, and inhibit glycolysis. In the present study proglycosyn was found to inhibit fatty acid synthesis, stimulate fatty acid oxidation, and lower fructose 2,6-bisphosphate levels, but to have no significant effects on cell swelling and the levels of cAMP in hepatocytes prepared from fed rats. Verapamil and atropine blocked the effects of proglycosyn on glycogen metabolism, but these compounds inhibit proglycosyn accumulation by hepatocytes. Proglycosyn stimulated phosphoprotein phosphatase activity in postmitochondrial extracts, as measured by dephosphorylation of phosphorylase a and glycogen synthase D, but this action required a very high concentration of the compound, making it unlikely to be the actual mechanism involved. It is proposed that a metabolite of proglycosyn is responsible for its metabolic effects.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1992

Effects of daily physical activity on insulin action in the elderly.

The effects of daily physical activity on peripheral insulin action were investigated in aged individuals. Glucose infusion rates (GIR) during the euglycemic insulin clamp procedure in aged bedridden, aged controls, and aged athletes were compared with those in young controls and young athletes at insulin infusion rates of 40 and 400 mU.m-2.min-1 to estimate insulin action at physiological and maximal insulin concentrations, respectively. At both insulin infusion rates, GIR was significantly higher in aged athletes and significantly lower in aged bedridden subjects than in aged controls. Although there was no statistical difference in GIR at 400 mU.m-2 x min-1 between young athletes and young controls, GIR at 40 mU.m-2 x min-1 was higher in young athletes than in young controls. Comparison of the aged and young groups showed that although GIR at 400 mU.m-2 x min-1 was significantly lower in aged controls than in young controls, there was no significant difference between the aged athletes and the young athletes. We conclude that insulin responsiveness (insulin action at the postreceptor binding site) may decrease with the aging process and may be further affected by physical inactivity. Although physical training may improve insulin responsiveness in aged individuals up to levels similar to those in young athletes, physical training in young individuals may improve only insulin sensitivity.

Adult↗

PubMed1990

[Effect of aging and physical inactivity on glucose tolerance and insulin sensitivity].

It has been well documented that glucose intolerance is associated with aging, but it is not yet clear whether this phenomenon is due to the aging process itself or is secondary to the appearance of other age-related conditions among which physical inactivity is one of most important variables. To evaluate the effect of aging process and/or physical inactivity on insulin action, this study was undertaken using the euglycemic insulin clamp technique and the oral glucose tolerance test (OGTT). Subjects without diabetes mellitus and other serious diseases consisted of 14 non-obese aged individuals and 10 young controls (YC group), ranging in age from 63 to 85 yrs, and from 19 to 21 yrs, respectively. The aged individuals were further divided into two groups (one was termed as the AS group, in which 7 aged subjects had been confined to bed for at least 3 months and the other was termed as the AC group in which 7 aged controls kept their daily physical activity such as walking). The results of OGTT did not show any remarkable differences between AC and YC groups. In the AS group, however, glucose intolerance and low insulin response during OGTT were observed. In view of the tissue insulin action, MCR, which is thought as a reliable marker for tissue insulin action, evaluated by euglycemic insulin clamp was 5.31 +/- 0.68, 8.57 +/- 1.20, 9.60 +/- 0.35 ml/kg/min in the AS, AC and YC groups, respectively (AS less than AC, p less than 0.05, AS less than YC, p less than 0.01, AC less than YCM, N.S.).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989