OBJECTIVES:We investigated the effect of obesity on the serum levels of total and free IGF-1 and their relationship to the circulating levels of insulin and IGF binding proteins (IGFBPs) in age and sex-matched groups. SUBJECTS: The study included 43 obese subjects (ideal body weight; IBW b 120%) and 45 controls (IBW`100%). All of the subjects were male. MEASUREMENT: Total IGF-1, free IGF-1, IGFBP-1, IGFBP-2, IGFBP-3, and insulin were measured in obese subjects and normal control subjects. RESULTS: No signi®cant differences in the circulating levels of total and IGFBP-3 were observed between the obese and control groups. In contrast to total IGF-1, free IGF-1 in obese subjects was signi®cantly increased compared to normal controls (P`0.05). Serum total and free IGF-1 were inversely correlated with age (r À0.42, P 0.001, and À0.44, P 0.001). Fasting serum insulin concentrations were elevated in all the obese subjects (P`0.05) and positively correlated with IBW (r 0.57, P 0.001). The levels of serum GH and IGFBP-1 were suppressed in all the obese subjects (P`0.05). IGFBP-1 was inversely correlated with IBW (r À0.51, P 0.001) and serum insulin concentrations (r À0.48, P 0.001). The IGFBP-2 concentrations were also suppressed in obese subjects and inversely related to free IGF-1 (r À0.48, P 0.001). Using multiple linear regression analysis, total IGF-1 and insulin concentrations were positively correlated (r 0.58, P 0.001) and free IGF-1 and IGFBP-1 concentrations were negatively correlated (r À0.57, P 0.001). CONCLUSION: We con®rmed that total IGF-1 and IGFBP-3 concentrations were not signi®cantly different between the obese and control groups, despite GH hyposecretion in obesity. We also found that free IGF-1 concentrations were higher in obese subjects than in normal controls. It seems likely that overnutrition and chronic hyperinsulinaemia in obesity may alter this regulated growth response by insulin stimulation of IGF-1 production and suppression of hepatic IGFBP-1 and IGFBP-2 production, which may inhibit IGF-1 bioactivity.
In a healthy screening population, H. pylori infection had a strong negative association with reflux esophagitis, but H. pylori eradication increased the prevalence of erosive esophagitis to the level of H. pylori-negative individuals. Long-term clinical significance of newly developed erosive esophagitis after H. pylori eradication should be evaluated prospectively.
In obesity, growth hormone (GH) secretion is impaired which is considered a consequence rather than a cause of obesity. GH regulates the expression of GH receptor and the synthesis of insulin-like growth factor I (IGF-I) in adipocytes. Although GH hyposecretion in obesity may decrease the generation of IGF-I in each adipocyte, increased amounts of IGF-I and GH-binding protein could be secreted from the excessively enlarged amounts of adipose tissue. This may contribute to the normal/high serum-IGF-I and high GH-binding protein levels in obesity. Hyperinsulinemia and increased GH receptor activity may also affect the GH-IGF-I axis. Favorable effects of GH treatment have been observed in obese children and adults. GH treatment decreases adiposity, reduces triglyceride accumulation by inhibiting lipoprotein lipase and enhances lipolysis both via increased hormone-sensitive lipase activity and via induction of beta adrenoreceptors. GH treatment also has a favorable effect on obesity-associated dyslipidemia, but the effects on insulin sensitivity have been conflicting.
Growth hormone (GH) can induce an accelerated lipolysis. Impaired secretion of GH in obesity results in the consequent loss of the lipolytic effect of GH. Dietary restriction as a basic treatment for obesity is complicated by poor compliance, protein catabolism, and slow rates or weight loss. GH has an anabolic effect by increasing insulin-like growth factor (IGF)-I. We investigated the effects of GH treatment and dietary restriction on lipolytic and anabolic actions, as well as the consequent changes in insulin and GH secretion in obesity. 24 obese subjects (22 women and 2 men; 22–46 years old) were fed a diet of 25 kcal/kg ideal body weight (IBW) with 1.2 g protein/kg IBW daily and were treated with recombinant human GH (n = 12, 0.18 U/kg IBW/week) or placebo (n = 12, vehicle injection) in a 12-week randomized, double-blind and placebo-controlled trial. GH treatment caused a 1.6-fold increase in the fraction of body weight lost as fat and a greater loss of visceral fat area than placebo treatment (35.3 vs. 28.5%, p < 0.05). In the placebo group, there was a loss in lean body mass (–2.62 ± 1.51 kg) and a negative nitrogen balance (–4.52 ± 3.51 g/day). By contrast, the GH group increased in lean body mass (1.13 ± 1.04 kg) and had a positive nitrogen balance (1.81 ± 2.06 g/day). GH injections caused a 1.6-fold increase in IGF-I, despite caloric restriction. GH response to L-dopa stimulation was blunted in all subjects and it was increased after treatment in both groups. GH treatment did not induce a further increase in insulin levels during an oral glucose tolerance test (OGTT) but significantly decreased free fatty acid (FFA) levels during OGTT. The decrease in FFA area under the curve during OGTT was positively correlated with visceral fat loss. This study demonstrates that in obese subjects given a hypocaloric diet, GH accelerates body fat loss, exerts anabolic effects and improves GH secretion. These findings suggest a possible therapeutic role of low-dose GH with caloric restriction for obesity.
H. pylori infection increased the risk of hyperplastic polyps in both cross-sectional and longitudinal settings, and its eradication induced regression of hyperplastic polyps.
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