Original Article Obesity and Metabolic Syndrome Diabetes Metab J 2014;38:74-80 http://dx.doi.org/10.4093/dmj.2014.38.1.74 pISSN 2233-6079 · eISSN 2233-6087
DIABETES & METABOLISM JOURNAL
Women Are Diagnosed with Type 2 Diabetes at Higher Body Mass Indices and Older Ages than Men: Korea National Health and Nutrition Examination Survey 2007–2010 Su Kyoung Kwon Department of Endocrinology and Metabolism, Kosin University Gospel Hospital, Kosin University College of Medicine, Busan, Korea
Background: Many epidemiologic studies have shown that women with type 2 diabetes have an increased risk of developing cardiovascular disease compared with men with diabetes. The aim of this study is to elucidate whether disparities of adiposity, age and insulin resistance (IR) at the time of diabetes diagnosis exist between women and men in the adult Korean population. Methods: Data from The Korea National Health and Nutrition Examination Survey, performed in Korea from 2007 to 2010, were used. In the survey, anthropometric data and blood samples were obtained during a fasting state. IR and β-cell function were calculated using the homeostasis model assessment (HOMA-IR and HOMA-β, respectvely). Results: The mean age of diabetes diagnosis was 58.5 years in women and was 55.1 years in men (P=0.015). The mean body mass index (BMI) of newly diagnosed diabetes subjects was 26.1 kg/m2 in women and 25.0 kg/m2 in men (P=0.001). The BMI was inversely related to age in both genders, and the higher BMI in women than men was consistent throughout all age groups divided by decade. The HOMA-IR in women with diabetes is higher than in men with diabetes (7.25±0.77 vs. 5.20±0.32; P=0.012). Conclusion: Korean adult women are diagnosed with type 2 diabetes at higher BMI and older age than men and are more insulin-resistant at the time of diabetes diagnosis. This may help explain why women with diabetes have an increased risk of developing cardiovascular disease after the diagnosis of diabetes, compared to men. Keywords: Adiposity; Cardiovascular diseases; Diabetes; Insulin resistance; Korea
INTRODUCTION Increasing numbers of patients with diabetes pose a major threat to global health, and the rising incidence is closely related to increasing obesity in Western and Eastern countries [1-4]. There have been many studies that demonstrated various influences of weight gain and body fat distribution on the onset of diabetes, with differences reported according to age, gender, and ethnic group [5-7]. In the general population, men are less obese but are more vulnerable to abdominal obesity and show Corresponding author: Su Kyoung Kwon Department of Endocrinology and Metabolism, Kosin University Gospel Hospital, Kosin University College of Medicine, 262 Gamcheon-ro, Seo-gu, Busan 602-702, Korea E-mail:
[email protected] Received: Oct. 14, 2013; Accepted: Jan. 6, 2014
an increased risk of cardiovascular disease (CVD) and diabetes compared with women [7-9]. Although there is some variability, both men and women gain progressively more fat as they age [10]. Patients with diabetes are in a well-known high-risk group for CVD [11]. In the nondiabetic population, men generally have a greater relative risk of CVD than women [9]. However, this gender difference in CVD risk is lessened in diabetic groups [12-14], and there have been several studies demonstrating that the relative risk of CVD in type 2 diabetes is greater in women This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Copyright © 2014 Korean Diabetes Association
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Gender differences of adiposity at the diagnosis of diabetes
than men [15,16]. The cause of the greater increase of relative CVD risk in diabetic women compared with diabetic men is not fully understood. Some propose that the findings may be explained as a result of differing adverse effects of diabetes on cardiovascular risk profiles, differing treatment intensity, or differing changes of metabolic parameters during transition from nondiabetes to diabetes between men and women [17-21]. The purpose of this study is to evaluate whether gender differences in adiposity exist and to gain a better understanding regarding how these differences relate to insulin resistance and the time of diabetes diagnosis according to age and sex in an adult Korean newly diagnosed diabetes population.
12,030 Subject were excluded by following criteria ■ High risk groups of steroid use: rheumatoid arthritis, bronchial asthma ■ History of cancer treatment ■ Pregnancy ■ Active infection: active pulmonary tuberculosis, pneumonia ■ Biochemical evidence of renal and liver disease: Cr >1.5, bilirubin >2, AST/ALT >2.5 normal value
21,797 Subjects Newly diagnosed diabetes subjects were selected by predefined criteria
402 Subjects Age under 30 years were excluded
METHODS
396 Subjects (M:F, 205:191) were analyzed
Study subjects The data from the Korea National Health and Nutrition Examination Survey (KNHANES) conducted from 2007 to 2010 by the Korea Centers for Disease Control and Prevention were used. A total of 33,829 subjects between the ages of 20 and 85 years were included. The survey was performed in three parts: 1) a health interview survey, 2) a health examination survey, and 3) a nutrition survey. The KNHANES is a nationwide study of a noninstitutionalized population and used a stratified and multistage probability sampling design with a rolling survey sampling model. The sampling units were based on household unit data from the 2005 National Census Registry, which includes age, sex, and geographic area. Using a structured questionnaire, trained staff members conducted in person interviews of all subjects. Subjects who were at high-risk for steroid use with conditions such as bronchial asthma, allergic disease, and autoimmune disease like rheumatoid arthritis were excluded. Subjects with cancer, pregnancy or an infectious disease, such as tuberculosis or pneumonia, were also excluded. Those who showed an increased creatinine level greater than 1.5 mg/dL, serum bilirubin greater than 2.0 mg/dL, or alanine aminotransferase (ALT) and aspartate aminotransferase (AST) greater than 100 U/L were also excluded. After exclusion, newly diagnosed diabetes subjects were drawn secondarily from a total of 21,797 subjects. Newly diagnosed diabetes was defined by plasma glucose ≥126 mg/dL in the health examination survey with no reported previous history of diabetes in health interview survey. Lastly, we excluded subjects under the age of 30 years in order to reduce the possibility of including type 1 diabetes. http://e-dmj.org
33,829 Subjects from KNHANES 2007-2010
Diabetes Metab J 2014;38:74-80
Fig. 1. Selection and enrollment of study subjects. KNHANES, Korea National Health and Nutrition Examination Survey; CR, creatinine; AST/ALT, aspartate aminotransferase/alanine aminotransferase; M, male; F, female. Finally, a total of 396 subjects (205 men and 191 women) were included in the present study (Fig. 1). The subjects were divided into age groups,
