• Nutrition Research and Practice
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• v.8 no.4
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• pp.469-475
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• 2014

BACKGROUND/OBJECTIVE: The goal of the present study was to investigate the effects of moderate caloric restriction on ${\beta}$-cell function and insulin sensitivity in middle-aged obese Korean women. SUBJECTS/METHODS: Fifty-seven obese pre-menopausal Korean women participated in a 12-week calorie restriction program. Data on total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), and fasting serum levels of glucose, insulin, C-peptide, blood pressure, leptin and anthropometrics were collected. A dietary intake assessment was based on three days of food recording. Additionally, ${\beta}$-cell function [homeostasis model assessment of ${\beta}$-cell (HOMA-${\beta}$), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose ($AUC_{ins/glu}$)] and insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR), Quantitative insulin-sensitivity check index (QUICKI) and Matsuda index (MI)] were recorded. RESULTS: When calories were reduced by an average of 422 kcal/day for 12 weeks, BMI (-2.7%), body fat mass (-10.2%), and waist circumference (-5%) all decreased significantly (P < 0.05). After calorie restriction, weight, body fat percentage, hip circumference, BP, TC, HDL-C, LDL-C, plasma glucose at fasting, insulin at fasting and 120 min, $AUC_{glu}$ and the insulin area under the curve all decreased significantly (all P < 0.05), while insulin sensitivity (HOMA-IR, QUICKI and Matsuda index) measured by OGTT improved significantly (P < 0.01). CONCLUSIONS: Moderate weight loss due to caloric restriction with reduction in insulin resistance improves glucose tolerance and insulin sensitivity in middle-aged obese women and thereby may help prevent the development of type 2 diabetes mellitus.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.3
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• pp.223-229
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• 2008

Objective: This pilot study was performed to investigate the effect of metformin on insulin resistance, hormone levels, and lipid profiles in non-obese patients with polycystic ovary syndrome. Methods: This study included 16 non-obese patients with polycystic ovary syndrome diagnosed at our hospital from June 2006 to September 2007. Blood samples were collected before and 6 months after metformin treatment for analysis of fasting serum glucose levels, fasting serum insulin levels, a glycemic response to 75 g oral glucose tolerance test (OGTT), and hormonal blood profile including FSH, LH, estradiol, testosterone, free testosterone, serum lipid profiles. Insulin resistance was estimated by calculating fasting glucose/insulin ratio (FGIR), 2 hr glucose/insulin ratio after 75 g glucose load. And we investigated insulin resistance and pancreatic beta cell function by calculating HOMA beta cell function and HOMA IR. Results: After the treatment of metformin, there was significant increase in 2 hr glucose/insulin ratio after 75 g glucose load (p=0.04) and decrease in HOMA IR (p=0.000). But serum lipid profiles did not change significantly. Also the metformin treatment induced a significant reduction in serum free testosterone and LH levels, and LH/FSH ratio (p=0.001, p=0.000, p=0.034). Conclusion: This pilot study showed that metformin might be effective in improving insulin sensitivity, ameliorating hyperandrogenemia in non-obese patients with polycystic ovary syndrome. Further investigations with larger number of patients and long-term observations are necessary to determine the role of metformin.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.171-177
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• 2015

Sodium butyrate is a short-chain fatty acid derivative found in foods, such as Parmesan cheese and butter and is produced by anaerobic bacteria fermentation of dietary fibers in the large intestine. There have been reports that butyrate prevented obesity, protected insulin sensitivity, and ameliorated dyslipidemia in dietary obese mice. This study investigated the effects of sodium butyrate on fasting blood glucose level and serum lipid profile in streptozotocin(STZ)-induced diabetic mice. Male C57BL/6 mice were fed AIN-93G for four weeks prior to intraperitoneal injections with STZ (100 mg/kg body weight). Diabetic mice had supplements of 5% sodium butyrate for four weeks. The 5% sodium butyrate diet significantly improved fasting blood glucose level and lipid profile in STZ-induced diabetic mice. Inflammation has been recognized to decrease beta cell insulin secretion and increase insulin resistance. Circulating cytokines can directly affect beta cell function, leading to secretory dysfunction and increased apoptosis. Thus, anti-inflammatory therapies represented a potential approach for the therapy of diabetes and its complications. In this animal study, the 5% sodium butyrate supplementation also inhibited inflammatory cytokine production in STZ-induced diabetic mice. These results suggested that sodium butyrate can be a potential candidate for the prevention of diabetes and its complications.