Diabetes & Metabolism Journal

Eun Kyung Byun (Byun EK)

3 Articles

Usefulness of Insulin Sensitivity Indexes derived from Oral Glucose Tolerance Test in Women with Polycystic Ovary Syndrome.: Hyo Jeong Kim, Eun Kyung Byun, Jee Young Oh, Yeon Ah Sung, Hye Won Chung; Korean Diabetes J. 2006;30(4):277-284. Published online July 1, 2006; DOI: https://doi.org/10.4093/jkda.2006.30.4.277

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BACKGROUND
Insulin resistance is prevalent in women with polycystic ovary syndrome (PCOS), and it makes them to have high risk for development of type 2 diabetes. Evaluation of insulin sensitivity would be important to predict their risks. Although the euglycemic-hyperinsulinemic clamp technique is the gold standard for measuring insulin sensitivity, it is too hard to practice in large epidemiologic studies. The aim of this study is to verify the validity of various insulin sensitivity indexes from oral glucose tolerance test (OGTT) in women with PCOS. METHODS: We performed euglycemic-hyperinsulinemic clamp (target glucose; 90 mg/dL, insulin ;~1 mU/kg.min) to obtain insulin-mediated glucose disposal rate (M-value) in 62 non-diabetic women with PCOS (BMI < 23 kg/m2; n = 37, BMI > or = 23 kg/m2; n = 25). Homeostasis model assessment [HOMA(IR)], quantitative insulin sensitivity check index (QUICKI), glucose to insulin ratio (G/I ratio), whole body insulin sensitivity index [ISI(COMP)], metabolic clearance rate of glucose [MCR(est)-OGTT(1,2)], and insulin sensitivity indexes [ISI(est)-OGTT(1,2)] were calculated from plasma glucose and insulin levels from standard 75-g OGTT. The correlations of various insulin sensitivity indexes from OGTT with M-value were evaluated. RESULTS: In lean women with PCOS (BMI < 23 kg/m2, n = 37), ISI(COMP) (r = 0.36, P < 0.05), MCRest-OGTT1 (r = 0.49, P < 0.01), ISI(est)-OGTT(1) (r = 0.50, P < 0.01), MCR(est)-OGTT(2) (r = 0.45, P < 0.01) and ISI(est)-OGTT(2) (r = 0.40, P < 0.05) were significantly correlated with M-value. In overweight and obese women with PCOS (BMI > or = 23 kg/m2, n = 25), HOMA(IR) (r = -0.40, P < 0.05), QUICKI (r = 0.40, P < 0.05), MCR(est)-OGTT(1) (r = 0.76, P < 0.001), ISI(est)-OGTT(1) (r = 0.63, P < 0.001), MCR(est)-OGTT(2) (r = 0.58, P < 0.01) and ISI(est)-OGTT(2) (r = 0.42, P < 0.05) showed significant correlations with M-value. CONCLUSION: MCR(est)-OGTT(1) and ISI(est)-OGTT(1) were the most reliable and easily accessible insulin sensitivity indexes obtained from OGTT for measuring of insulin sensitivity in women with PCOS regardless of obesity.

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Insulin resistance in a large cohort of women with polycystic ovary syndrome: a comparison between euglycaemic-hyperinsulinaemic clamp and surrogate indexes
Flavia Tosi, Enzo Bonora, Paolo Moghetti
Human Reproduction.2017; 32(12): 2515. CrossRef

Insulin Resistance in Normal Weight Women with Polycystic Ovary Syndrome.: Eun Kyung Byun, Hye Jin Lee, Jee Young Oh, Young Sun Hong, Hye Won Chung, Yeon Ah Sung; Korean Diabetes J. 2004;28(4):315-323. Published online August 1, 2004

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Abstract PDF: BACKGROUND
Insulin resistance is considered a regular component of polycystic ovary syndrome (PCOS). However, several studies have failed to confirm insulin resistance in non-obese women with PCOS. The aim of the study was to identify whether insulin resistance is present in normal weight women with PCOS and the factors associated with insulin sensitivity. METHODS: Twenty-two normal weight (body mass index, BMI < 25 kg/m2) women with PCOS, and 16 age and BMI comparable control women with regular menstrual cycles were examined during their early follicular phase. The levels of serum hormones and lipids were measured. The visceral fat area was assessed by computed tomography at umbilical level. The standard 75g oral glucose tolerance test was performed to determine the glucose tolerance status. The insulin sensitivity was measured using the euglycemic hyperinsulinemic clamp technique (target glucose 90 mg/dL, insulin~1 mu/kg/min). RESULTS: The levels of free testosterone (1.9+/-0.6 pg/mL vs. 0.8+/-0.3 pg/mL, p<0.001), androstenedione (14.5+/-3.7 nmol/L vs. 8.8+/-1.3 nmol/L, p<0.001), LH (10.7+/-4.5 IU/L vs 4.6+/-4.8 IU/L, p<0.001) and FSH (5.8+/-1.7 IU/L vs. 4.2+/-2.4 IU/L, p<0.05) of the women with PCOS were significantly higher than those of the control subjects. The fasting plasma glucose (4.92+/-0.31 mmol/L vs. 4.42+/-0.61 mmol/L, p<0.01) and post glucose load plasma insulin (233.2+/-119.5pmol/L vs. 109.0+/-46.4 pmol/L, p<001) levels of women with PCOS were significantly higher than those of the control subjects. The glucose disposal rate (M value) was significantly lower in women with PCOS compared to the controls (5.3+/-1.2 mg/kg min vs. 6.7+/-1.6 mg/kg min, p<0.05), even after adjusting for age and BMI. There was no significant correlation of the M value with the anthropometric and a metabolic indices, and a multiple regression analysis of the M value showed no significant variables. CONCLUSION: Our non-obese women with PCOS showed significant insulin resistance compared to their age and BMI comparable control subjects, and-their insulin resistance may be an intrinsic defect not associated with other features, such as hyperandrogenemia or body fat distribution patterns.

Impaired Insulin Secretion in Normoglycemic Offspring of Patients with Type 2 Diabetes.: Eun Kyung Byun, Young Sun Hong, Jee Young Oh, Yeon Ah Sung, Yeon Jin Jang; Korean Diabetes J. 2003;27(1):39-48. Published online February 1, 2003

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Abstract PDF: BACKGROUND
Although it is well known that insulin secretory defects and insulin resistance are major pathogenetic factors of type 2 diabetes, their relative importance still remains controversial in various ethnic groups. Increased levels of proinsulin, and the proinsulin/insulin (PI/I) ratio, are considered markers of pancreatic dysfunction, and predictors for the development of type 2 diabetes. To reveal which pathogenetic abnormality is most prominent in Koreans with type 2 diabetes, we measured the insulin sensitivity and secretory capacity in the normal glucose tolerant offspring of patients with type 2 diabetes. METHODS: Sixty-two offspring, with normal glucose tolerance (mean age 40.4+/-6.5 BMI 23.4+/-2.7 kg/m2), of type 2 diabetes parents, were compared with and 20, age and BMI-matched control subjects, with on family history of diabetes. We measured the serum levels of proinsulin (PI), specific insulin (I), and C-peptide(C) and calculated the PI/I and C/I ratios, as parameters of hepatic insulin clearance. The insulin sensitivity index (SI) was measured by the intravenous glucose tolerance test (IVGTT) using the MINMOD program, as a marker of insulin sensitivity. The acute insulin response to glucose (AIRg), AIRg by product, SI and the area under the insulin curve (AUCinsulin) were measured by IVGTT, and used as a marker of the insulin secretory capacity. We also evaluated the association between the proinsulin and insulin secretory capacities. RESULTS: Offspring of the type 2 diabetic patients had significantly lower AIRg SI and AUCinsulin (p<0.05), and tended to have lower AIRg (p=0.06), than the control subjects. However, there was no significant difference in the SI between the two groups. However, with the proinsulin, and the insulin, PI/I and C/I ratios, not significant differences were found between the offspring and the control subjects, and the PI/I ratio was not correlated with AIRg, AIRg x SI or SI. CONCLUSION: Insulin secretory defect could be a more prominent factor in the development of type 2 diabetes in Koreans, with no change in the proinsulin secretion.

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