[Show abstract][Hide abstract] ABSTRACT: Data on the impact of resistance training on insulin resistance in overweight or obese children are inconclusive.
Thirty overweight South Korean adolescents (mean age of 13.10 years) were divided by sex, and then randomly assigned to one of three treatment groups, which were the diet only (DO), diet with aerobic exercise (AE), or diet with resistance training (RT) group. Physiologic and metabolic parameters were assessed at baseline and after 12 weeks of exercise training and diet modification.
Both exercise groups (aerobic and resistance) showed significant improvements in their insulin area under the curve and insulin sensitivity index values when compared to their baseline values while the DO group showed no significant changes in these variables. Age-, sex-, and body mass index (BMI)-adjusted intergroup comparison analyses showed a marked reduction in BMI and a significant reduction in muscle mass in the AE group when compared to the RT group and the DO group, respectively.
A 12-week exercise training program of either resistance or aerobic activity improved insulin sensitivity in overweight adolescents, although it failed to show superiority over a DO program. Aerobic exercise decreased both body weight and BMI, and it was noted that this group also had a significant reduction in muscle mass when compared to the DO group.
[Show abstract][Hide abstract] ABSTRACT: Although it has been hypothesized that an atherogenic lipid profile might be associated with lower bone mineral density (BMD), the previous results are controversial. We investigated the association between lipid profile and BMD in premenopausal and postmenopausal women in a large Korean population. This study considered 10,402 women who underwent measurements of lipid profile and BMD from October 2003 to October 2005 at Healthcare System Gangnam Center, Seoul National University Hospital. Participants with potential confounding factors affecting BMD (n = 3,128) were excluded. The associations between lipid profiles (total cholesterol [TC], low-density lipoprotein [LDL-C] and high-density lipoprotein [HDL-C] cholesterol, and triglyceride [TG]) and BMD at various skeletal sites (lumbar spine [L1-L4], proximal total hip, femoral neck, and trochanter) were explored by Pearson's correlation and partial correlation, adjusting for age, body mass index, and menarche age. Multiple linear regression analyses adjusting for all other covariates were also performed. Data on 4,613 premenopausal and 2,661 postmenopausal women aged 20-91 years were finally included in the analysis. In multivariate analyses, there was no significant relationship between lipid profiles and BMD, except that HDL-C was positively associated with BMD at only the lumbar spine in postmenopausal women and that the quartiles of TG were negatively associated with BMD at the total hip and trochanter in only premenopausal women. We conclude that although there were some weak associations between lipid profiles and BMD, the results of this study hardly support the hypothesis that an atherogenic lipid profile is associated with osteoporosis.
Calcified Tissue International 10/2010; 87(6):507-12. · 2.75 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To investigate whether or not antiaminoacyl-tRNA synthetase (aaRS) autoantibodies could be detected in patients with type 1 diabetes mellitus (DM) and be used as a diagnostic marker for type 1 DM, autoantibodies against aaRSs were measured in the plasma of normal subjects, patients with type 1 DM and patients with type 2 DM.
An enzyme-linked immunosorbent assay was performed to detect anti-aaRS autoantibodies in the plasma of normal subjects, and patients with type 1 DM, and patients with type 2 DM.
From the 65 (normal), 58 (type 1 DM) and 57 (type 2 DM) subjects, anti-aaRS autoantibodies were found in 37.9% of patients with type 1 DM compared with 1.54% of the non-diabetic controls, and 5.26% of the patients with type 2 DM (p <0.0001). In addition, anti-aaRS autoantibodies were identified in 30% of patients with type 1 DM without classical type 1 DM autoantibodies.
Anti-aaRS autoantibodies were identified in 37.9% of patients with type 1 DM. The results of this study demonstrate for the first time that autoantibodies against aaRSs are specifically associated with type 1 DM.
[Show abstract][Hide abstract] ABSTRACT: Exercise training enhances insulin sensitivity. Changes in retinol-binding protein-4 (RBP4) and adiponectin levels are linked to insulin resistance.
We tested whether the insulin-sensitizing effect of exercise is associated with age-related changes in circulating RBP4 and adiponectin levels in women. DESIGN, SUBJECTS, AND INTERVENTION: We studied 36 healthy young (22.4 +/- 2.8 yr) and 38 middle-aged (59.8 +/- 5.9 yr) women. All subjects performed 60 min of aerobic exercise three times per week for 10 wk at about 70% maximal exercise capacity.
After a 10-wk training program, maximal exercise capacity was significantly increased in both young and middle-aged women, suggesting increased oxidative capacity. Insulin sensitivity was also improved, as indicated by decreases in plasma insulin levels and homeostasis model assessment for insulin resistance index. Serum adiponectin and RBP4 concentrations were increased and decreased more in older than younger women, respectively (P < 0.01). Concurrently, circulating transthyretin levels were also decreased in older subjects in response to exercise training. The older women showed higher correlations between changes in adiponectin or RBP4 levels and obesity indices or metabolic parameters than the younger group. When subjects showing increasing adiponectin or decreasing RBP4 levels were classified as responders, there were higher correlations between these changes in responders than in nonresponders.
We conclude that the mechanism for the insulin-sensitizing effects of exercise could involve increased adiponectin and reduced RBP4 levels in exercise-trained women. These data suggest that alterations in circulating RBP4 and adiponectin levels could play an important role in regulating insulin sensitivity.