Obesity as a risk factor for non-insulin-dependent diabetes mellitus in Korea

Body mass index and waist circumference according to glucose tolerance status in Korea: the 2005 Korean Health and Nutrition Examination Survey

The purpose of this study was to investigate the stage of glucose intolerance in which persons showed a maximum obesity in Korea. A total of 4,479 participants, who were involved in the 2005 Korean National Health and Nutrition Examination Survey, was examined. The participants were divided into 5 groups by fasting plasma glucose (FPG); normal fasting glucose (NFG)1, FPG < 90 mg/dL; NFG2, FPG 90-99 mg/dL; impaired fasting glucose (IFG)1, FPG 100-109 mg/dL; IFG2, FPG 110-125 mg/dL; and diabetes mellitus, FPG ≥ 126 mg/dL or with anti-diabetes drugs. In those with FPG < 110 mg/dL, body mass index (BMI) and waist circumference (WC) were increased with increase of FPG (BMI in men; NFG1, 23.3 ± 0.1; NFG2, 24.4 ± 0.1; IFG1, 25.0 ± 0.2 kg/m(2), in women; NFG1, 23.0 ± 0.1; NFG2, 24.0 ± 0.1; IFG1, 24.8 ± 0.2 kg/m(2), WC in men; NFG1, 82.1 ± 0.3; NFG2, 85.3 ± 0.3; IFG1, 86.7 ± 0.5 cm, in women; NFG1, 77.1 ± 0.2; NFG2, 79.4 ± 0.3; IFG1, 81.8 ± 0.6 cm). In IFG2 and diabetes range, there was no more increase of BMI and WC with increase of FPG in each sex. The data suggest that degree of obesity increases with an increase of FPG in range of FPG < 100 mg/dL, peaked in FPG of 100-109 mg/dL, and then plateaus in higher FPG range in general Korean population.

Associations among body mass index, insulin resistance, and pancreatic β-cell function in Korean patients with new-onset type 2 diabetes

BACKGROUND/AIMS

We investigated the associations among body mass index (BMI), insulin resistance, and β-cell function in Korean patients newly presenting with type 2 diabetes.

METHODS

In total, 132 patients with new-onset type 2 diabetes mellitus were investigated. A standard 75-g oral glucose tolerance test was performed, and the indices of insulin secretion and insulin resistance were calculated.

RESULTS

A higher BMI was associated with higher homeostasis model assessment values for insulin resistance (HOMA-IR), homeostasis model assessment of β-cell function (HOMA-β), and insulinogenic index as well as lower levels of insulin sensitivity index composite (ISI(comp)) and disposition index (DI). In multiple regression models, BMI had independent positive associations with HOMA-IR, ISI(comp), and HOMA-β and inverse associations with the DI.

CONCLUSIONS

Our results showed that BMI had independent positive associations with indices of insulin resistance and an inverse association with β-cell function adjusted for insulin resistance in Korean patients newly presenting with type 2 diabetes.

The magnitude of association between overweight and obesity and the risk of diabetes: a meta-analysis of prospective cohort studies

The objectives of this meta-analysis were to examine the magnitude of the relative risk (RR) of developing type 2 diabetes for overweight and obese populations, compared to those with normal weight, and to determine causes of the variation in RR between various cohort studies. The magnitude of the RR was analyzed by combining 18 prospective cohort studies that matched defined criteria. The variance in RR between studies was explored. The overall RR of diabetes for obese persons compared to those with normal weight was 7.19, 95% CI: 5.74, 9.00 and for overweight was 2.99, 95% CI: 2.42, 3.72. The variation in RR among studies was explored and it was found that the effect of heterogeneity was highly related with sample size, method of assessment of body mass index (BMI) and method of ascertainment of type 2 diabetes. By combining only cohort studies with more than 400 cases of incident diabetes (>median), adjusted by at least three main confounding variables (age, family history of type 2 diabetes, physical activity), measured BMI, and diabetes determined by clinical diagnosis, the RR was 7.28, 95% CI: 6.47, 8.28 for obesity and 2.92, 95% CI: 2.57, 3.32 for overweight.

Risk factors of type 2 diabetes among Korean adults: The 2001 Korean national health and nutrition examination survey

This study aimed to identify risk factors for type 2 diabetes (T2D) in Korea, a rapidly changing country. Data of 5,132 adults aged 20-85 were used from the 2001 Korean Health and Nutrition Examination Survey. Multiple logistic regression was carried out to identify risk factors for T2D. Three models were specified: (i) socioeconomic and demographic factors (model 1: age, gender, education, poverty income ratio, employment), (ii) behavioral risk factors and covariates (model 2: obesity, physical activity, smoking, alcohol drinking, dietary quality, family history of T2D, co-morbidity) and (iii) socioeconomic, demographic, and behavioral factors (model 3). The prevalence of T2D was 7.4%. Less education (OR 1.41, 95% CI 1.08-1.84), age (OR 2.19, 95% CI 1.56-3.08 in 40-59 yrs, OR 4.05, 95% CI 2.76-5.95 in 60 yrs + comparing to 20-39 yrs) and abdominal obesity (OR 2.24, 95% CI 1.79-2.82) were risk factors for T2D even after controlling for other factors simultaneously. There was a significant association of T2D with ever smoking (OR 1.34, 95% CI 1.06-1.67). The relationship of age with T2D was modified by gender in model 1 and the relationship of smoking with T2D was modified by obesity in model 2. Less educated, older, obese or ever smokers were more likely to have T2D. Gender mediated the relationship of age, and obesity mediated the relationship of smoking, with T2D. Intervention programs for T2D in Korea should take the interactions among risk factors into account.

Glucose control in korean immigrants with type 2 diabetes

Despite the rising incidence of type 2 diabetes in Korean immigrants, little is known about glucose control in these individuals. This descriptive study examined factors influencing glucose control in Korean immigrants with type 2 diabetes. Participants were 143 Korean immigrants with type 2 diabetes who completed questionnaires, a finger stick blood test for glycosylated hemoglobin (HbA1c), and anthropometric measures. The mean HbA1c level was 7.6 % (SD = 1.5; range = 5.6 to 12.5). Less than half of the participants (41.3%) met the American Diabetes Association's goal of less than 7%. After adjusting for demographic and health variables, family diet support, waist-to-hip ratio (WHR), the duration of diabetes, the number of diabetic medications, and age significantly influenced glucose control. Findings support the positive role of family involvement in diabetes management. Patients with long-standing diabetes, higher WHR, and more diabetic medications deserve special attention because they tend to have higher HbA1c levels.

Technological intervention for obese patients with type 2 diabetes

This study applied a 6-month educational intervention that used the technology of the short message service (via cellular phones) and the Internet for obese patients with type 2 diabetes. Eighteen patients were randomly assigned to an intervention group and 16 were assigned to a control group (N = 34). Patients in the intervention group were asked to access a web site by using personal cellular phones or computer Internet services to input their blood glucose levels daily. Participants were then sent optimal recommendations via cellular phone and the Internet weekly. After 6 months, the intervention group had a statistically significant decrease in glycosylated hemoglobin, fasting plasma glucose, 2-hour postmeal glucose, and total cholesterol, as compared with the control group.

Perceptions of coronary heart disease risk in Korean immigrants with type 2 diabetes

PURPOSE

The purpose of this study was to examine coronary heart disease (CHD) risk perception, risk factor status, and factors associated with CHD risk perception in Korean immigrants with type 2 diabetes mellitus.

METHODS

A community sample of 143 Korean adults with type 2 diabetes, aged 30 to 80 years old, completed questionnaires and biological measures. A multiple regression analysis was conducted to evaluate the relationships between CHD knowledge, general health, smoking, medications for CHD risk factors, demographic variables (independent variables), and the perception of CHD risk (dependent variable).

RESULTS

Participants had low perception of CHD risk, with most (76.9%) indicating their risk to be the same or lower than people of the same age and sex in the general population. Overall, CHD risk factor control was suboptimal according to American Diabetes Association guidelines. Only 41.3% of participants met the HbA1c goal of less than 7%. More than half (55%) had uncontrolled blood pressure, and a similar proportion (53.6%) had higher low-density lipoprotein cholesterol than the target goal. CHD knowledge and self-reported general health influenced the perception of CHD risk. More CHD knowledge and poor general health were associated with higher perception of CHD risk.

CONCLUSIONS

To increase the perception of CHD risk in Korean immigrants with type 2 diabetes, diabetes educators and clinicians should educate such patients about CHD risk factors and discuss their risk status at every visit. Those who report their health to be good deserve particular attention.

Effectiveness of mobile and internet intervention in patients with obese type 2 diabetes

PURPOSE

The present study evaluated whether an intervention using the SMS by personal cellular phone and internet would improve the levels of plasma glucose of obese type 2 diabetes at 3, 6, 9, and 12 months.

METHODS

This is a quasi-experimental design with pre- and follow-up tests. Participants were recruited from the endocrinology outpatient department of tertiary care hospital located in an urban city of South Korea. Eighteen patients were randomly assigned to an intervention group and 16 to a control group. The goal of the intervention was to decrease body weight and keep blood glucose concentrations close to the normal range. Patients were requested to record their blood glucose level in a weekly diary on the website by personal cellular phones or computer internet. The researcher sent optimal recommendations to each patient, by both the cellular phone and the Internet weekly. The intervention was applied for 1 year.

RESULTS

Glycosylated hemoglobin (HbA(1)c) decreased 1.22 percentage points at 3 months, 1.09 percentage points at 6 months, 1.47 percentage points at 9 months, and 1.49 percentage points at 12 months compared with baseline in the intervention group (all time points, p<0.05). The percentage change in the control group was, however, not significant. Patients in the intervention group had a decrease of 2-h post-prandial test (2HPPT) of 120.1mg/dl at 3 months, 58.9 mg/dl at 6 months, 62.0mg/dl at 9 months, and 102.9 mg/dl at 12 months compared with baseline (all time points, p<0.05). The mean change in the control group was, however, not significant.

CONCLUSION

This web-based intervention using SMS of personal cellular phone and Internet improved HbA(1)c and 2HPPT at 3, 6, 9, and 12 months in patients with obese type 2 diabetes.

Plasma n-3 polyunsaturated fatty acid and cardiovascular disease risk factors in Japanese, Korean and Mongolian workers

The favorable role of n-3 polyunsaturated fatty acid (PUFA) in cardiovascular disease (CVD) has been demonstrated in animal experiments and in humans in Western countries, but its effect remains controversial in Asian populations. An observational study of Japanese, Koreans and Mongolians with extended histories of remarkably different frequencies of fish intake was conducted to examine whether differences in plasma n-3 PUFA affects CVD risk factors. We conducted a cross-sectional study in workplace settings and determined body mass index (BMI), blood pressure, total cholesterol, LDL-cholesterol, HDL-cholesterol, triglyceride (TG), glucose, insulin, homeostasis model assessment-insulin resistance (HOMA-IR) and fatty acid composition in plasma. A total of 411 Japanese, 418 Korean and 252 Mongolian workers aged 30-60 yr participated in this study. The Japanese ate fish more frequently and had remarkably higher values of eicosapentaenoic acid, docosahexaenoic acid and n-3 PUFA, and lower values of BMI and HOMA-IR, followed by the Koreans, and then the Mongolians. In age groups, the Japanese and Koreans showed a similar tendency of increase in n-3 PUFA with increasing age. General linear measurement multivariate analysis after adjustment for gender, age, smoking, drinking, exercise habits and BMI showed n-3 PUFA was associated with HDL-C and TG in the Japanese, while it was associated with systolic blood pressure in the Koreans, and TG in the Mongolians. In conclusion, an increase in n-3 PUFA was associated with HDL-C and TG in the Japanese and Mongolians, but these beneficial effects were not constant across the three Asian ethnic groups.

How many cases of Type 2 diabetes mellitus are due to being overweight in middle age? Evidence from the Midspan prospective cohort studies using mention of diabetes mellitus on hospital discharge or death records

AIMS

To relate body mass index (BMI) in middle age to development of diabetes mellitus.

METHODS

Participants were 6927 men and 8227 women from the Renfrew/Paisley general population study and 3993 men from the Collaborative occupational study. They were aged 45-64 years and did not have reported diabetes mellitus. Cases who developed diabetes mellitus, identified from acute hospital discharge data and from death certificates in the period from screening in 1970-1976 to 31 March 2004, were related to BMI at screening.

RESULTS

Of Renfrew/Paisley study men 5.4%, 4.8% of women and 5% of Collaborative study men developed diabetes mellitus. Odds ratios for diabetes mellitus were higher in the overweight group (BMI 25 to < 30 kg/m(2)) than in the normal weight group (BMI 18.5 to < 25 kg/m(2)) and highest in the obese group (BMI >or= 30 kg/m(2)). Compared with the normal weight group, age-adjusted odds ratios for overweight and obese Renfrew/Paisley men were 2.73 [95% confidence interval (CI) 2.05, 3.64] and 7.26 (95% CI 5.26, 10.04), respectively. Further subdividing the normal, overweight and obese groups showed increasing odds ratios with increasing BMI, even at the higher normal level. Assuming a causal relation, around 60% of cases of diabetes could have been prevented if everyone had been of normal weight.

CONCLUSIONS

Overweight and obesity account for a major proportion of diabetes mellitus, as identified from hospital discharge and death records. With recent increases in the prevalence of overweight, the burden of disease related to diabetes mellitus is likely to increase markedly. Primordial prevention of obesity would be a major strategy for reducing the incidence of diabetes mellitus in populations.

Prevalence of the Metabolic Syndrome using the Modified ATP III Definitions for Workers in Japan, Korea and Mongolia

A clustering of insulin resistance, hypertension and dyslipidemia has been labeled as the metabolic syndrome. Asians have a lower frequency of obesity than do Caucasians, but have an increasing tendency toward metabolic syndrome. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. We conducted a cross-sectional study of individuals aged 30-60 yr in workplace settings. We examined and analyzed the health data of 1,384 Japanese, Koreans and Mongolians for metabolic syndrome based on the modified definitions of the working definition proposed by the Third Report of the National Cholesterol Educational Program Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (ATP III definition). The prevalence of metabolic syndrome using the ATP III-BMI30 and ATP III-BMI25 definitions was 7% and 12% for Japanese, 7% and 13% for Koreans, and 12% and 16% for Mongolians, respectively. With the exception of obesity, the prevalences of individual metabolic abnormalities within each of the three Asian groups were similar to each other and to reported rates of prevalence in the U.S.A. Nevertheless, the values of sensitivity and specificity by the metabolic syndrome definitions are remarkably different relative to ethnicity. A universal metabolic syndrome definition is inappropriate for comparisons of metabolic syndrome among Asian ethnic groups. We believe that the ATP III-BMI25 definition is suitable for the determination of metabolic syndrome among Japanese and Koreans, and that the ATP III-BMI30 is more appropriate for Mongolians.

Body mass index is the most important determining factor for the degree of insulin resistance in non-obese type 2 diabetic patients in Korea

With obesity, increased insulin secretion is needed to compensate for the additional demands and to maintain euglycemia. In contrast to Caucasians, the majority of type 2 diabetic patients belong to the non-obese category in Korea. There appears to be an ethnic difference underlying the pathogenesis in type 2 diabetes mellitus. However, there is only limited data on these subjects. The degree of insulin resistance in 267 Korean non-obese (body mass index [BMI] < 25 kg/m(2)) >/= patients with type 2 diabetes mellitus was analyzed, and the factors responsible for the insulin resistance were examined. The mean age and BMI of the patients were 50.8 +/- 10.6 years and 22.6 +/- 1.8 kg/m(2). Homeostasis model assessment-insulin resistance (HOMA-IR) >/= 2.5 was defined as being insulin resistant according to our data (mean +/- 1.5 SD of 1,917 normal subjects). There was no significant difference according to age, the duration of disease, and the glycosylated hemoglobin (HbA(lc)) levels between the subjects with or without insulin resistance. The HOMA-IR values in the patients with insulin resistance and normal insulin sensitivity were 4.2 +/- 1.4 and 1.5 +/- 0.6, respectively. In the insulin-resistant group, the log-transformed triglyceride (TG) levels were higher and the high-density lipoprotein-cholesterol (HDL-C) levels were lower than those of the insulin-sensitive group (log-transformed TG: 5.2 +/-.6 v 4.9 +/-.7 and HDL-C: 1.13 +/- 0.3 v 1.25 +/- 0.3mmol/L). These differences were still observed after adjusting for BMI. The HOMA-IR value was independently predicted by BMI and HDL-C levels, which explained 7% and 3% in the variability of insulin resistance, respectively. However, the TG levels were not independently associated with the HOMA-IR. Logistic regression analysis showed that the significant factor associated with HOMA-IR was only BMI. These results suggest that the BMI is the most important determinant of insulin resistance, while TG and HDL-C levels might be good markers of insulin resistance in non-obese patients with type 2 diabetes mellitus in Korea.