Healani K. Chang

Prevalence of Glucose Intolerance Among Native Hawaiians in Two Rural Communities

OBJECTIVE To estimate prevalence of type 2 diabetes and impaired glucose tolerance (IGT) among a population of native Hawaiians in two rural communities. RESEARCH DESIGN AND METHODS Prevalence of glucose intolerance was assessed in two rural communities by history (confirmed by record review) or with a 75-g oral glucose tolerance test according to World Health Organization criteria. Anthropometric and demographic data were also obtained. A short survey was used to estimate the prevalence of known diabetes among nonparticipants. Prevalence rates were adjusted using the standard world population of Segi. RESULTS A total of 574 native Hawaiians age ≥30 years participated. The crude prevalence of IGT and type 2 diabetes were 15.5 and 20.4%, respectively. Only IGT prevalence was significantly higher (P = 0.03) among women (18.7%) than among men (10.9%). Prevalence of glucose intolerance was significantly associated with BM1, waist circumference, and waistto-hip ratio (WHR). After adjusting for age and BMI, waist circumference and WHR were significantly and independently associated with type 2 diabetes prevalence only among women. Prevalence of type 2 diabetes was not significantly associated with the percentage of Hawaiian ancestry after adjusting for age. CONCLUSIONS This study observed a high prevalence of glucose intolerance associated with being overweight among native Hawaiians. Age-adjusted type 2 diabetes prevalence was four times higher than among the U.S. National Health and Nutrition Examination Survey (NHANES) II population. Prevalence was high despite high rates of admixture with other ethnic groups of Hawaii, suggesting that these other Asian and Pacific Island populations share similar susceptibility to type 2 diabetes risk.

Biological, psychosocial, and sociodemographic variables associated with depressive symptoms in persons with type 2 diabetes

Studies have found an association between glycemic status and indices of health-related quality of life in people with diabetes mellitus and comorbid depression. No study to date has examined the relative strength of influences of glycemic status and health-related quality of life on depression in people with diabetes mellitus, nor have important moderators in this relationship been examined. This study examined the relative strength of correlations between glycemic status and health-related quality of life and depressive symptoms and the degree to which those correlations were moderated by sociodemographic variables in 146 people with type 2 diabetes. Depressive symptoms were measured with the Centers for Epidemiological Studies—Depression (CES-D) scale. Health-related quality of life was measured with the SF-36 Health Survey. Hemoglobin A1c (HbA1c) was used as a measure of glycemic status and body mass index and waist–hip ratio were measured. Results indicated that SF-36 scores accounted for a greater proportion of the variance in CES-D scores. The association between CES-D and SF-36 scores was moderated by HbA1c, sex, education, marital status, and social support. The implications and limitations of these results were discussed in the context of past studies.

Optimum BMI Cut Points to Screen Asian Americans for Type 2 Diabetes

OBJECTIVE Asian Americans manifest type 2 diabetes at low BMI levels but may not undergo diagnostic testing for diabetes if the currently recommended BMI screening cut point of ≥25 kg/m2 is followed. We aimed to ascertain an appropriate lower BMI cut point among Asian-American adults without a prior diabetes diagnosis. RESEARCH DESIGN AND METHODS We consolidated data from 1,663 participants, ages ≥45 years, without a prior diabetes diagnosis, from population- and community-based studies, including the Mediators of Atherosclerosis in South Asians Living in America study, the North Kohala Study, the Seattle Japanese American Community Diabetes Study, and the University of California San Diego Filipino Health Study. Clinical measures included a 2-h 75-g oral glucose tolerance test, BMI, and glycosylated hemoglobin (HbA1c). RESULTS Mean age was 59.7 years, mean BMI was 25.4 kg/m2, 58% were women, and type 2 diabetes prevalence (American Diabetes Association 2010 criteria) was 16.9%. At BMI ≥25 kg/m2, sensitivity (63.7%), specificity (52.8%), and Youden index (0.16) values were low; limiting screening to BMI ≥25 kg/m2 would miss 36% of Asian Americans with type 2 diabetes. For screening purposes, higher sensitivity is desirable to minimize missing cases, especially if the diagnostic test is relatively simple and inexpensive. At BMI ≥23 kg/m2, sensitivity (84.7%) was high in the total sample and by sex and Asian-American subgroup and would miss only ∼15% of Asian Americans with diabetes. CONCLUSIONS The BMI cut point for identifying Asian Americans who should be screened for undiagnosed type 2 diabetes should be <25 kg/m2, and ≥23 kg/m2 may be the most practical.

The Insulin Resistance Syndrome in Native Hawaiians

OBJECTIVE To investigate whether fasting hyperinsulinemia is associated with a clustering of cardiovascular disease (CVD) risk factors, manifesting as the insulin resistance syndrome (IRS), in a population of native Hawaiians. RESEARCH DESIGN AND METHODS A total of 574 native Hawaiians ≥ 30 years of age were examined for blood pressure, waist-to-hip ratio (WHR), BMI, oral glucose tolerance, and fasting lipid, insulin, and C-peptide concentrations. All statistical analyses (n = 384) excluded 190 individuals who had NIDDM or who were taking hypertension medication. Using logistic regression analysis, fasting insulin and C-peptide levels were compared with CVD risk factors (glucose intolerance, hypertension, central adiposity, elevated triglyceride levels, and low HDL cholesterol levels) after adjusting for age and obesity. RESULTS Sixty-six percent of native Hawaiians were overweight or obese, and 70% were found to have central adiposity. Fasting insulin concentrations were correlated with BMI, WHR, blood pressure, and triglyceride, HDL cholesterol, and glucose concentrations. Fasting insulin was also significantly associated with an increasing number of CVD risk factors in each participant (P < 0.001). Fasting insulin and C-peptide concentrations were independently associated with glucose intolerance, high triglyceride levels, and low HDL cholesterol levels. However, only fasting C-peptide concentrations were independently associated with hypertension and central adiposity. Apparent differences in the correlates of fasting insulin and C-peptide may be related to multiple factors and warrant further evaluation. CONCLUSIONS This study provides cross-sectional data confirming the existence of the IRS in native Hawaiians. However, further longitudinal studies are needed to examine the relationship of insulin resistance and/or surrogate markers to increased rates of NIDDM and CVD mortality in native Hawaiians.

Relationship between depressive symptoms and diabetes among native Hawaiians

Increased prevalence of depression has been reported among diabetes patients. We examined this association between diabetes and depressive symptoms in a population-based study where glucose tolerance status was determined with World Health Organization (WHO) criteria. Fasting plasma glucose (FPG) was determined from blood collected from 574 native Hawaiians. The Centers for Epidemiological Studies-Depression (CES-D) scale was used to assess depressive symptoms in association with diabetes history and hemoglobin A1c (HbA1c). A significant association was observed between depressive symptoms and HBA1c that persisted after adjusting for age, BMI, gender, education, and after exclusion of participants reporting a history of diabetes. Diabetes history was no longer associated with CES-D depressive symptoms after adjusting for HbA1c. These results support the hypothesis that depressive symptoms associated with diabetes may be partially explained by a shared neuroendocrinological disturbance.

Relationship between plasma glucose concentrations and Native Hawaiian Ancestry: The Native Hawaiian Health Research Project

Objective: To investigate the relationship between fasting glucose and 2 h glucose with percentage of Hawaiian ancestry and ethnic admixture.Design: Cross-sectional epidemiological study of type 2 diabetes and heart disease risk factor prevalence among Native Hawaiians.Subjects: A total of 578 Native Hawaiians residing in two rural communities were examined between 1993 and 1996. Sample sizes in statistical analyses varied due to missing data and selection criteria based on ethnic ancestry.Measurements: Percentage of Hawaiian ancestry and non-Hawaiian ethnic admixture, assessed by self-report. Fasting and 2 h post glucose challenge plasma glucose levels. Anthropometric measures (height, weight, waist and hip circumferences). Self-report of diet and physical activity. Medical history.Results: Increased Hawaiian blood quantum was significantly associated with increased fasting glucose (P=0.0047), increased body mass index (BMI; P<0.0001), waist-to-hip ratio (WHR; P=0.0103), and age (P<0.0001), but not with leisure time physical activity and total dietary caloric intake. This association was attenuated after adjusting for BMI and WHR, but not by age-adjustment alone. However, when the effects of descent from other ethnic groups was examined in a subset of participants, full-Hawaiians had significantly higher fasting glucose concentrations (7.28 mmol/l) than part-Hawaiians after adjustments for age, gender, BMI and WHR. In contrast, part-Hawaiians of predominantly Asian ancestry had the highest 2 h glucose concentrations (7.62 mmol/l).Conclusion: These results suggest that ethnic admixture may be an important, but extremely complex, factor concerning the high prevalence of type 2 diabetes observed among this population. The complexity of this relationship may have obscured the relationship between ancestry and glucose tolerance in earlier observations of this population.

Ethnic Differences in the Relationship between Depressive Symptoms and Health-Related Quality of Life in People with Type 2 Diabetes

Objective . To examine ethnic differences in the relationship between depressive symptoms and specific aspects of heath-related quality of life in people with type 2 diabetes. Design . Cross-sectional data from 190 people with type 2 diabetes of Native Hawaiian (50%), Filipino (16%), Japanese (18%), and mixed-ethnic (16%) ancestries from the rural community of North Kōhala, Hawai‘i were examined in this study. Depressive symptoms were measured with the Center for Epidemiological Studies—Depression (CES-D) scale. Health-related quality of life was measured with the Short Form-36 Health Survey (SF-36). Eight health-related quality of life constructs were examined: Physical Functioning, Role-Physical Functioning, Role-Emotional Functioning, Social Functioning, Bodily Pain, Vitality, General Health, and Health Transition. Results . Hierarchical regression analyses of the interaction between ethnicity and the SF-36 subscales of Physical Functioning, Role-Emotional Functioning, Bodily Pain, Vitality, and General Health indicated statistically significant associations with CES-D scores after controlling for sociodemographic factors, glycemic status, and social support. Conclusion . Ethnicity moderated the relationship between depressive symptoms and the health-related quality of life aspects of physical and role-emotional functioning, bodily pain, vitality, and general health perception in people with type 2 diabetes. This relationship was strongest for Filipinos followed by Native Hawaiians and people of mixed-ethnic ancestries.

Depressive symptoms and cigarette smoking among Native Hawaiians.

The present study estimated the prevalence of depressive symptoms and cigarette smoking and examined the relationship between depressive symptoms and cigarette smoking among native Hawaiians. Cross-sectional data from 524 rural, native Hawaiian from the Native Hawaiian Health Research Project are presented. Depressive symptoms were measured using the self-report Centre for Epidemiological Studies-Depression Scale. Information on smoking behavior and sociodemographic variables was collected. The prevalence of depressive symptoms was 15%, and significantly higher among participants with lower educational attainment. The prevalence of current smokers was 32%, and significantly higher among younger adults and participants with lower educational attainment. Regression analyses reported a significant relationship between CES-D scores and smoking status as well as between CES-D scores and number of cigarettes smoked daily. However, when education and age were included in the regression models, the relationships were attenuated. The findings and implications of this study are discussed.