Predictors of Incident Type 2 Diabetes Mellitus in Japanese Americans with Normal Fasting Glucose Level

황유철,Wilfred Y. Fujimoto,Steven E. Kahn,Donna L. Leonetti,Edward J. Boyko 대한당뇨병학회 2018 Diabetes and Metabolism Journal Vol.42 No.3

Background: Little is known about the natural course of normal fasting glucose (NFG) in Asians and the risk factors for future diabetes. Methods: A total of 370 Japanese Americans (163 men, 207 women) with NFG levels and no history of diabetes, aged 34 to 75 years, were enrolled. Oral glucose tolerance tests were performed at baseline, 2.5, 5, and 10 years after enrollment. Results: During 10 years of follow-up, 16.1% of participants met criteria for diabetes diagnosis, and 39.6% of subjects still had NFG levels at the time of diabetes diagnosis. During 5 years of follow-up, age (odds ratio [OR], 1.05; 95% confidence interval [CI], 1.01 to 1.10; P=0.026) and family history of diabetes (OR, 3.24; 95% CI, 1.42 to 7.40; P=0.005) were independently associated with future diabetes diagnosis; however, fasting glucose level was not an independent predictor. During 10 years of follow-up, family history of diabetes (OR, 2.76; 95% CI, 1.37 to 5.54; P=0.004), fasting insulin level (OR, 1.01; 95% CI, 1.00 to 1.02; P=0.037), and fasting glucose level (OR, 3.69; 95% CI, 1.13 to 12.01; P=0.030) were associated with diabetes diagnosis independent of conventional risk factors for diabetes. Conclusion: A substantial number of subjects with NFG at baseline still remained in the NFG range at the time of diabetes diagnosis. A family history of diabetes and fasting insulin and glucose levels were associated with diabetes diagnosis during 10 years of follow-up; however, fasting glucose level was not associated with diabetes risk within the relatively short-term follow-up period of 5 years in subjects with NFG.

Higher High Density Lipoprotein 2 (HDL2) to Total HDL Cholesterol Ratio Is Associated with a Lower Risk for Incident Hypertension

황유철,Wilfred Y. Fujimoto,Steven E. Kahn,Donna L. Leonetti,Edward J. Boyko 대한당뇨병학회 2019 Diabetes and Metabolism Journal Vol.43 No.1

Background: Recent studies have suggested that high density lipoprotein (HDL) cholesterol is inversely associated with the development of hypertension. We aimed to determine the association between different HDL cholesterol subclasses and risk of future hypertension. Methods: A total of 270 Japanese Americans (130 men, 140 women) without hypertension between the ages of 34 to 75 years were enrolled. Blood pressure was measured with a mercury sphygmomanometer, and average blood pressure was calculated. Incident hypertension was determined 5 to 6 and 10 to 11 years after enrollment. HDL2, HDL3, and total HDL cholesterol were measured at baseline. Results: During 10 years of follow-up, the cumulative incidence of hypertension was 28.1% (76/270). In univariate analysis, age, diabetes, waist circumference, systolic and diastolic blood pressure, fasting glucose, insulin resistance index, total and low density lipoprotein cholesterol, and visceral adipose tissue were significant predictors for incident hypertension. Among the HDL cholesterol subclass, HDL2 cholesterol was inversely associated with hypertension incidence, but both total and HDL3 cholesterol were not. In addition, HDL2/HDL cholesterol was inversely associated with future hypertension risk. In multivariate analysis, age (odds ratio [OR], 1.71; 95% confidence interval [CI], 1.26 to 2.31; P=0.001), systolic blood pressure (OR, 1.83; 95% CI, 1.31 to 2.56; P<0.001), and HDL2/HDL cholesterol (OR, 0.71; 95% CI, 0.52 to 0.98; P=0.035), were associated with future development of hypertension. Conclusion: A higher proportion of HDL2 cholesterol among total HDL cholesterol predicted a lower risk for incident hypertension. However, concentrations of total HDL, HDL2, and HDL3 cholesterol were not independent predictors of incident hypertension.

Apolipoprotein B Levels Predict Future Development of Hypertension Independent of Visceral Adiposity and Insulin Sensitivity

한승진,Wilfred Y. Fujimoto,Steven E. Kahn,Donna L. Leonetti,Edward J. Boyko 대한내분비학회 2020 Endocrinology and metabolism Vol.35 No.2

Background: High plasma apolipoprotein B (apoB) levels have been shown to be associated with hypertension, central obesity, andinsulin resistance in cross-sectional research. However, it is unclear whether apoB levels predict future hypertension independent ofbody composition and insulin sensitivity. Therefore, we prospectively investigated whether plasma apoB concentrations independently predicted the risk of hypertension in a cohort of Japanese Americans. Methods: A total of 233 normotensive Japanese Americans (77 men, 156 women; mean age, 46.4±11.0 years) were followed over10 years to monitor them for the development of hypertension. Fasting plasma concentrations of apoB, glucose, and insulin weremeasured at baseline. Insulin sensitivity was estimated using the homeostasis model assessment of insulin resistance (HOMA-IR). The abdominal visceral and subcutaneous fat areas were measured at baseline using computed tomography. Logistic regression analysis was used to estimate the association between apoB concentrations and the odds of incident hypertension. Results: The 10-year cumulative incidence of hypertension was 21.5%. The baseline apoB level was found to be positively associated with the odds of incident hypertension over 10 years after adjustment for age, sex, body mass index, systolic blood pressure, abdominal visceral fat area, abdominal subcutaneous fat area, total plasma cholesterol concentration, diabetes status, and HOMA-IR atbaseline (odds ratio and 95% confidence interval for a 1-standard deviation increase, 1.89 [1.06 to 3.37]; P=0.030). Conclusion: Higher apoB concentrations predicted greater risks of future hypertension independent of abdominal visceral fat areaand insulin sensitivity in Japanese Americans

Association of Thigh Muscle Mass with Insulin Resistance and Incident Type 2 Diabetes Mellitus in Japanese Americans

한승진,Edward J. Boyko,김수경,Wilfred Y. Fujimoto,Steven E. Kahn,Donna L. Leonetti 대한당뇨병학회 2018 Diabetes and Metabolism Journal Vol.42 No.6

Background: Skeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association. Methods: This prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years. Results: Thigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels. Conclusion: Thigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

Intra-Abdominal Fat and High Density Lipoprotein Cholesterol Are Associated in a Non-Linear Pattern in Japanese-Americans

송선옥,황유철,Steven E. Kahn,Donna L. Leonetti,Wilfred Y. Fujimoto,Edward J. Boyko 대한당뇨병학회 2020 Diabetes and Metabolism Journal Vol.44 No.2

Background: We describe the association between high density lipoprotein cholesterol (HDL-C) concentration and computed tomography (CT)-measured fat depots. Methods: We examined the cross-sectional associations between HDL-C concentration and intra-abdominal (IAF), abdominal subcutaneous (SCF), and thigh fat (TF) areas in 641 Japanese-American men and women. IAF, SCF, and TF were measured by CT at the level of the umbilicus and mid-thigh. The associations between fat area measurements and HDL-C were examined using multivariate linear regression analysis adjusting for age, sex, diabetes family history, homeostasis model assessment of insulin resistance (HOMA-IR), and body mass index (BMI). Non-linearity was assessed using fractional polynomials. Results: Mean±standard deviation of HDL-C concentration and IAF in men and women were 1.30±0.34 mg/dL, 105±55.3 cm2, and 1.67±0.43 mg/dL, 74.4±46.6 cm2 and differed significantly by gender for both comparisons (P<0.001). In univariate analysis, HDL-C concentration was significantly associated with CT-measured fat depots. In multivariate analysis, IAF was significantly and non-linearly associated with HDL-C concentration adjusted for age, sex, BMI, HOMA-IR, SCF, and TF (IAF: β=–0.1012, P <0.001; IAF2: β=0.0008, P<0.001). SCF was also negatively and linearly associated with HDL-C (β=–0.4919, P=0.001). Conclusion: HDL-C does not linearly decline with increasing IAF in Japanese-Americans. A more complex pattern better fits this association.

Lower High-Density Lipoprotein Cholesterol Concentration Is Independently Associated with Greater Future Accumulation of Intra-Abdominal Fat

송선옥,황유철,류한욱,Steven E. Kahn,Donna L. Leonetti,Wilfred Y. Fujimoto,Edward J. Boyko 대한내분비학회 2021 Endocrinology and metabolism Vol.36 No.4

Background: Both intra-abdominal fat (IAF) and high-density lipoprotein cholesterol (HDL-C) are known to be associated withcardiometabolic health. We evaluated whether the accumulation of computed tomography (CT)-measured IAF over 5 years was related to baseline HDL-C concentration in a prospective cohort study. Methods: All participants were Japanese-Americans between the ages of 34 and 74 years. Plasma HDL-C concentration and CTmeasurements of IAF, abdominal subcutaneous fat (SCF), and thigh SCF cross-sectional areas were assessed at baseline and at5-year follow-up visits. Results: A total of 397 subjects without diabetes were included. The mean±standard deviation HDL-C concentration was 51.6±13.0mg/dL in men and 66.0±17.0 mg/dL in women, and the IAF was 91.9±48.4 cm2 in men and 63.1±39.5 cm2 in women. The baselineplasma concentration of HDL-C was inversely associated with the change in IAF over 5 years using multivariable regression analysiswith adjustment for age, sex, family history of diabetes, weight change over 5 years, and baseline measurements of body mass index,IAF, abdominal SCF, abdominal circumference, thigh SCF, and homeostatic model assessment for insulin resistance. Conclusion: These results demonstrate that HDL-C concentration significantly predicts future accumulation of IAF over 5 years independent of age, sex, insulin sensitivity, and body composition in Japanese-American men and women without diabetes.