Determinants of incident non-insulin-dependent diabetes mellitus among blacks and whites in a national sample. The NHANES I Epidemiologic Follow-up Study

Prevalence of type 2 diabetes mellitus in Taiwan: ethnic variation and risk factors

The purpose of this study was to compare the prevalence of diabetes and risk factors for the disease in three ethnic groups in Taiwan; the Hakaas, Fukienese, and aborigines. A cross-sectional study of men and women aged 50-79 years were invited to attend a standardized interview and physical examination. Diabetes mellitus was defined as a fasting plasma glucose (concentration of greater than or = 126) or a previous diagnosis of diabetes. Demographic, socioeconomic, and risk factor data were obtained. A total of 1293 persons (468 Hakaas, 440 Fukienese, and 385 aborigines) completed the examination. Hakaas had the highest age-adjusted prevalence of diabetes, 17.9% in men and 15.5% in women, followed by Fukienese, 14.5% in men and 12.8% in women. Aborigines had a prevalence of 10.0% in men and 13.3% in women. Diabetes prevalence was positively associated with family history of diabetes, obesity, hypertension, and hypertriglyceridemia. The ethnic variation in diabetes prevalence was reduced after adjustment for age, sex and significant factors. The multivariate-adjusted odds ratios (95% confidence interval) were 1.27 (0.76-2.12) for Fukienese and 1.44 (0.89-2.33) for Hakaas compared with aborigines. Diabetes mellitus is a major public health problem in Taiwan and warrants prevention efforts tailored to the country's different ethnic groups.

Excess type 2 diabetes in African-American women and men aged 40-74 and socioeconomic status: evidence from the Third National Health and Nutrition Examination Survey

OBJECTIVE

To examine whether socioeconomic status (SES) explains differences in the prevalence of type 2 diabetes between African-American and non-Hispanic white women and men.

DESIGN

Cross sectional study of diabetes prevalence, SES, and other risk factors ascertained by physical examination and interview.

SETTING

Interviews were conducted in subjects' homes; physical examinations were conducted in mobile examination centres.

PARTICIPANTS

961 African-American women, 1641 non-Hispanic white women, 839 African-American men and 1537 non-Hispanic white men, aged 40 to 74 years, examined in the Third National Health and Nutrition Examination Survey (NHANES III), a representative sample of the non-institutionalised civilian population of the United States, 1988-1994.

MAIN RESULTS

Among women, African-American race/ethnicity was associated with an age adjusted odds ratio of 1.76 (95% confidence intervals 1.21, 2.57), which was reduced to 1.42 (95% confidence intervals 0.95, 2.13) when poverty income ratio was controlled. Controlling for education or occupational status had minimal effects on this association. When other risk factors were controlled, race/ethnicity was not significantly associated with type 2 diabetes prevalence. Among men, the age adjusted odds ratio associated with African-American race/ethnicity was 1.43 (95% confidence intervals 1.03, 1.99). Controlling for SES variables only modestly affected the odds ratio for African/American race/ethnicity among men, while adjusting for other risk factors increased the racial/ethnic differences.

CONCLUSIONS

Economic disadvantage may explain much of the excess prevalence of type 2 diabetes among African-American women, but not among men.

Epidemiologic study of type 2 diabetes in Taiwan

Diabetes mellitus (DM) in adults is a global health problem, although its prevalence varies widely between different populations and the rate has generally increased worldwide. In Taiwan, the mortality rate from DM has almost doubled over the past 10 years. The prevalence of DM in Taiwan was established between 1985 and 1996 and the rates were between 4.9 and 9.2%. The prevalence of impaired glucose tolerance (IGT) was 15.5% (men 15% and women 15.9%). The prevalence of DM and IGT increased significantly with age for both genders. The significant factors associated with newly diagnosed DM were age, BMI, family history of DM, systolic blood pressure (hypertension), physical activity and serum triglyceride levels. The prevalence of large vessel disease (LVD) in DM and non-diabetic subjects were 20.0 and 12.9%, respectively. Among diabetics, 15.8% had ischemic heart disease (IHD), 1.7% leg vessel disease (leg VD), and 2.5% stroke. In non-diabetics, the prevalence of the aforementioned macroangiopathies were 11.5, 0.2 and 1.2%, respectively. The diabetics had a significantly higher prevalence of macrovascular disease than non-diabetic subjects. The most significantly associated with the LVD was serum cholesterol levels. Serum cholesterol and HbA1(c) were significantly associated with the development of IHD. Cigarette smoking and female gender were significantly associated with the leg VD. The prevalence of diabetic retinopathy (DR) was 35.0%. (background DR 30%, preproliferative DR 2.8% and proliferative DR 2.2%, respectively.) The prevalence of DR for previously and newly diagnosed diabetics were 45.2 and 28.3% (men 42.8 vs. 33.3% and women 47.5 vs. 24.8%), respectively. From multiple logistic regression analysis, duration of DM was the most important risk factor related to DR. Diabetic subjects treated with insulin had a higher risk of developing retinopathy than those treated with dietary control. The prevalence of nephropathy and neuropathy were 12.9 and 23.5%, respectively. For those patients with and those without nephropathy and neuropathy, the duration of DM, percentage of insulin treatment, percentage of hypertension, and fasting plasma glucose were significantly different. Diabetic duration, hypertension, insulin treatment and glycemic control consistently correlated with nephropathy and neuropathy. In conclusion, the prevalence of DM in Taiwan was between 4.9 and 9.2%, and the prevalence of IGT was 15.5%. The possible risk factors of newly diagnosed diabetes were age, family history of DM, BMI, SBP (hypertension), physical activity and triglyceride levels. Diabetes in Chinese subjects share many characteristics similar to other Asian populations. The burden imposed by the chronic complications of diabetes is massive. In Taiwan, the mortality rates from DM have increased greatly over the past 10 years. Reduction of the modificable risk factors such as BMI, hypertenion and dyslipidemia, and increase of physical activity and good glycemic control through public health efforts may help to reduce the risk of DM and its chronic complications.

Relation of generalized and central obesity to cardiovascular risk factors and prevalent coronary heart disease in a sample of American Indians: the Strong Heart Study

OBJECTIVE

To examine the hypothesis linking measures of obesity including body mass index (BMI), waist circumference (waist) and percentage body fat to coronary heart disease (CHD) prevalence and its risk factors in American Indians.

DESIGN

The Strong Heart Study assesses the prevalence of CHD and its risk factors in American Indians in Arizona, Oklahoma and South/North Dakota. Participants underwent a physical examination and an electrocardiogram; anthropometric and blood pressure measurements were taken, as were measurements of glucose, lipoproteins, fibrinogen, insulin, hemoglobin A1c and urinary albumin.

PARTICIPANTS

Data were available for 4549 men and women between 45 and 74 y of age.

MEASUREMENTS

Obesity, measured using body mass index, waist circumference and percentage body fat, was correlated with prevalent CHD and its risk factors.

RESULTS

More than 75% of participants were overweight (BMI>25 kg/m2). Measures of obesity were greater in women than in men, in younger than in older participants, and in participants with diabetes than in nondiabetic participants. CHD risk factors were associated with measures of obesity but, except for insulin concentration, changes in metabolic variables with increasing obesity were small. Associations were not stronger with waist than with BMI. The prevalence of CHD in those whose BMI and/or waist measurements lay in the lowest and highest quintiles, by gender and diabetic status, was similar.

CONCLUSIONS

Although CHD risk factors are associated with obesity in American Indians, distribution of obesity (ie waist) is no more closely related to risk factors than is generalized obesity (ie BMI), and changes in CHD risk factors with obesity were small. Thus, the relations among obesity, body fat distribution and CHD risk may differ in this population.

Diabetes mellitus, coronary heart disease incidence, and death from all causes in African American and European American women: The NHANES I epidemiologic follow-up study

Few data are available on risk for coronary heart disease in African American women with diabetes mellitus, a well-established coronary risk factor in European American women. This study tests the hypothesis that medical history of diabetes predicts coronary heart disease incidence in African American women in a national cohort. Participants in the NHANES I Epidemiologic Follow-up Study in this analysis were 1035 African American and 5732 European American women aged 25-74 years without a history of coronary heart disease. Average follow-up for survivors was 19 years (maximum 22 years). Risk of incident coronary heart disease by baseline diabetes status was estimated. Proportional hazards analyses for African American women aged 25-74 revealed significant associations of coronary heart disease risk with diabetes after adjusting for age (RR = 2.40; 95% CI, 1.58-3.64, P < 0.01). After adjusting for age, smoking, and low education, there was an elevated risk in diabetics age 25-74 (RR = 2. 34; 95% CI, 1.54-3.56, P < 0.01); this association did not differ significantly from that for European American women. Excess coronary incidence in African American compared to European American women aged 25-64 was statistically explained by controlling for diabetes history, age, education, and smoking but only partly explained by age and diabetes history. In African American women aged 25-74, diabetes was also associated with increased coronary heart disease, cardiovascular, and all-cause mortality. The population attributable risk of coronary heart disease incidence associated with a medical history of diabetes was 8.7% in African American women and 6.1% in European American women. Medical history of diabetes was a significant predictor of coronary heart disease incidence and mortality in African American women and explained some of the excess coronary incidence in younger African American compared to European American women.

High rates of infant macrosomia: a comparison of a Canadian native and a non-native population

The Cree of James Bay have the highest ever reported mean birth weight and a high prevalence of infant macrosomia. This study was designed to examine independent risk factors for infant macrosomia among the Cree, to compare these to risk factors among non-Native Canadians and to determine if ethnic differences persist after adjusting for differences in the distribution of other risk factors. Macrosomia was defined as birth weight >90(th) percentile for gestational age of a reference population. Independent determinants of macrosomia were examined in 385 Cree and 5644 non-Native women. The potential effect of ethnicity (Cree vs. non-Native) was determined after statistically adjusting for age, parity, pregravid weight, height, net rate of weight gain, gestational diabetes mellitus (GDM) and smoking status. The prevalence of macrosomia among the Cree was 34.3% vs. 11.1% among non-Natives. Although GDM significantly increased the risk for macrosomia among the Cree (odds ratio: 4.46, 95% CI: 2.24-9.26), it was not a significant risk factor among non-Natives (odds ratio: 1.15, 95% CI: 0.79-1.65). The risk for infant macrosomia remained elevated among the Cree compared with non-Natives after adjusting for other risk factors (odds ratio: 3.64, 95% CI: 2.69-4.90). In conclusion, the Cree have a high prevalence of macrosomia despite controlling for important differences in pregravid weight and GDM. Some of this variation may be due to genetic differences in fetal growth. The differential impact of GDM on macrosomia in the two ethnic groups may be due to differences in treatment strategies for GDM.

Physical activity and incident diabetes mellitus in postmenopausal women

OBJECTIVES

This study determined whether the incidence of diabetes is reduced among physically active older women.

METHODS

We assessed physical activity by mailed questionnaire and 12-year incidence of diabetes (ostensibly type 2 diabetes) in a cohort of 34257 women aged 55 to 69 years.

RESULTS

After adjustment for age, education, smoking, alcohol intake, estrogen use, dietary variables, and family history of diabetes, women who reported any physical activity had a relative risk of diabetes of 0.69 (95% confidence interval = 0.63, 0.77) compared with sedentary women.

CONCLUSIONS

These findings suggest that physical activity is important for type 2 diabetes prevention among older women.

Time to diagnosis and treatment of breast cancer: results from the National Breast and Cervical Cancer Early Detection Program, 1991-1995

OBJECTIVES

This study examined times to diagnosis and treatment for medically underserved women screened for breast cancer.

METHODS

Intervals from first positive screening test to diagnosis to initiation of treatment were determined for 1659 women 40 years and older diagnosed with breast cancer.

RESULTS

Women with abnormal mammograms had shorter diagnostic intervals than women with abnormal clinical breast examinations and normal mammograms. Women with self-reported breast symptoms had shorter diagnostic intervals than asymptomatic women. Diagnostic intervals were less than 60 days in 78% of cases. Treatment intervals were generally 2 weeks or less.

CONCLUSIONS

Most women diagnosed with breast cancer were followed up in a timely manner after screening. Further investigation is needed to identify and then address factors associated with longer diagnostic and treatment intervals to maximize the benefits of early detection.

Lipoprotein subpopulation distributions in lean, obese, and type 2 diabetic women: a comparison of African and white Americans

OBJECTIVE

Abnormal subpopulation distributions of plasma lipoproteins have been reported in white American (WA) women with obesity and type 2 diabetes that explain part of the elevated rate of cardiovascular disease in these patients. This study examined if these perturbations also occur in obese and diabetic African American (AA) women and compared the lipoprotein profiles with WA counterparts.

RESEARCH METHODS AND PROCEDURES

We determined the lipoprotein subpopulation distribution in the plasma of 51 lean women (29 WA, 22 AA, body mass index [BMI] < 30), 50 obese women (27 WA, 23 AA, BMI > 30), and 43 obese women with type 2 diabetes (27 WA, 16 AA), by nuclear magnetic resonance spectroscopy.

RESULTS

AA diabetic women, like WA diabetic women, had a larger average very low density lipoprotein (VLDL) size, elevated levels of small low density lipoprotein cholesterol (LDL-C), and lower levels of small high density lipoprotein cholesterol (HDL-C), when compared to lean controls (p<0.05). These differences were accompanied by higher VLDL-triglycerides (TG) and LDL-C in WA (p<0.05), but not in AA. Although the effects of obesity and diabetes on lipoprotein subpopulation were fairly similar for AA and WA, some racial differences, particularly with respect to HDL, were observed.

DISCUSSION

The atherogenic perturbations in lipoprotein profiles of obese AA women, particularly those with diabetes, were relatively similar to those found in WA women and may be contributing to the increased rate of cardiovascular disease (CVD) in AA with obesity and diabetes. The parameters of subpopulation distribution may provide better markers for CVD than lipid concentrations alone, particularly in AA women. Furthermore, subtle racial differences in lipoprotein profiles suggest that race-specific criteria may be needed to screen patients for CVD.

Assessing ecologic proxies for household income: a comparison of household and neighbourhood level income measures in the study of population health status

This paper examines the validity of using ecologic measures of socioeconomic status as proxies for individual-level measures in the study of population health. Based on a representative 5% sample of households in a Canadian province, the study integrated three sources of information: administrative records of individual health care utilization, records of deaths and 1986 census records which contained information on household income and average neighbourhood income. Thirteen measures of health status were developed from these sources of information. The hypothesis that risk estimates derived from ecologic income measures will be attenuated relative to estimates obtained from household income was not supported. These results provide evidence for the use of ecologic-level measures of income in studies which do not have access to individual-level income measures.

Evaluation of diabetes mellitus, serum glucose, and thyroid function among United States workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

OBJECTIVE

Some studies suggest that exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) may affect glucose metabolism and thyroid function. To further assess the relation between exposure to TCDD and endocrine function, data from the largest morbidity study of industrial workers exposed to TCDD were examined.

METHODS

A cross sectional study of workers employed > 15 years earlier in the manufacture of 2,4,5-trichlorophenol or one of its derivatives at two United States chemical plants was conducted. The referent group consisted of people with no occupational exposure to phenoxy herbicides and were recruited from the neighbourhoods where the workers lived.

RESULTS

A total of 281 workers and 260 unexposed referents participated. The mean current serum lipid adjusted TCDD concentration among workers was 220 pg/g lipid, and among referents was 7 pg/g lipid (p < 0.05). The half life extrapolated TCDD concentrations (the estimated TCDD concentration when occupational exposure to TCDD stopped) among workers averaged 1900 pg/g lipid (range: not detected--30,000 pg/g lipid). Overall, the prevalence of diabetes mellitus was not significantly different between the workers and referents. Also, there was not a significant positive trend between prevalence of diabetes and increasing serum TCDD concentration. However, diabetes was found in six of 10 (60%) workers with current serum TCDD concentrations > 1500 pg/g lipid. After excluding subjects being treated for diabetes, workers in the group with the highest half life extrapolated TCDD concentrations had a significantly increased adjusted mean serum glucose concentration compared with referents (p = 0.03). Workers were also found to have a significantly higher adjusted mean free thyroxine index compared with referents (p = 0.02), especially among workers in the group with the highest half life extrapolated TCDD concentrations. However, no evidence was found that workers exposed to TCDD were at increased risk of thyroid disease.

CONCLUSIONS

These findings provide modest evidence that exposure to TCDD may affect thyroid function and glucose metabolism.

Differential impact of obesity on glucose metabolism in black and white American adolescents

BACKGROUND

The authors have previously demonstrated abnormalities in glucose and insulin metabolism in nondiabetic black American (BA) adults versus white American (WA) adults. Whether similar glucoregulatory alterations extend to BA adolescents remain unknown. In addition, obesity, a known risk factor for insulin resistance and hyperinsulinemia, occurs in a greater proportion of BA adults and children when compared to WA. The objective of the present study was to examine the differential effects of obesity on glucose homeostasis in BA and WA adolescents.

METHODS

We examined glucose homeostasis in BA and WA adolescents using oral glucose tolerance test (OGTT), intravenous glucose tolerance test (IVGTT), and [6,6-2H2]-glucose infusion. The study consisted of four age-, sex-, and pubertal stage-matched groups: 15 lean BA, 29 lean WA, 7 obese BA, and 9 obese WA.

RESULTS

Both obese groups had significantly increased insulin and C-peptide area under the curve (AUC) during OGTT and IVGTT when compared to their same-race lean counterparts. During OGTT, obese BA demonstrated greater insulin and C-peptide when compared to obese WA. During IVGTT, first- and second-phase insulin were significantly greater in obese BA versus obese WA.

CONCLUSION

In summary, BA adolescents demonstrated insulin resistance which is markedly exaggerated in the face of obesity when compared to WA adolescents, implying a differential impact for obesity on glucose homeostasis that is unique to the obese BA adolescent group. In conclusion, there is a need for early aggressive weight management in obese BA adolescents.

Evaluating screening policies for the early detection of retinopathy in patients with non-insulin dependent diabetes

Retinopathy is a common complication of insulin-dependent (IDDM) and non-insulin-dependent (NIDDM) diabetes, but serious visual loss may be prevented or delayed with sufficiently early diagnosis and treatment. Screening for early signs of retinopathy is clearly beneficial for some people, but there is no established consensus about who should be screened, by whom, by what technique and with what frequency, especially for NIDDM. The model described in this paper simulates the development of eye disease in a population of NIDDM patients and the effects of different screening schemes in terms of years of sight saved and the numbers of people prevented from suffering severe visual loss. The initial results indicate that blanket screening of all NIDDM patients may not be effective.

Comparison of dietary risk factors for cardiovascular disease in African-American and white women

OBJECTIVE

To compare African-American and white women's knowledge, attitudes, and energy and nutrient intakes related to cardiovascular disease risk.

DESIGN

The 1989 through 1991 Continuing Survey of Food Intakes by Individuals and the Diet and Health Knowledge Survey (DHKS).

SUBJECTS

A nationally representative sample of 2,684 white and 449 African-American women who completed the DHKS and provided 3 days of dietary information.

STATISTICAL ANALYSES PERFORMED

Comparisons between groups were made using t tests and chi 2 analyses. Analysis of covariance was used to adjust for age, percentage of poverty, and education.

RESULTS

Significant differences in dietary risk for cardiovascular disease were identified. White women consumed significantly less cholesterol and more potassium than African-American women. African-American women had significantly lower knowledge scores, but they were more likely than white women to indicate that their diets should be lower in fat and salt and to consider nutrition very important when shopping. White women had more positive attitudes toward the impact of diet on health than African-American women. Accounting for differences between the groups in age, education, and income explained few differences between the groups.

APPLICATIONS

This study identified differences in nutrient intake, knowledge, and attitudes about diet and health that can influence the willingness and ability of women to choose foods for a more healthful diet. Dietitians can use these findings to target strategies for changing behavior. For example, many African-American women acknowledge the need to change their current diets, so dietitians can help them design implementation plans or specific action plans to accomplish needed changes.

Insulin sensitivity and intake of vitamins E and C in African American, Hispanic, and non-Hispanic white men and women: the Insulin Resistance and Atherosclerosis Study (IRAS)

Elevated fasting insulin concentrations and insulin resistance have been associated with non-insulin-dependent diabetes mellitus (NIDDM), obesity, atherosclerosis, and hypertension. Vitamin E supplementation in persons with and without NIDDM may be related to greater insulin sensitivity (SI). The cross-sectional associations of the intake of vitamins E and C with SI and insulin concentrations were evaluated among African American, Hispanic, and non-Hispanic white men and women with a wide spectrum of glucose tolerance included in the Insulin Resistance and Atherosclerosis Study (IRAS) (n = 1151). Insulin sensitivity was measured by minimal model analysis of a 12-sample, insulin-modified, frequently sampled intravenous glucose tolerance test. Nutrient intake (including vitamin supplement use) was assessed with a food-frequency questionnaire modified to include foods consumed by the three ethnic groups. Linear-regression models were used, including rank of SI and the log of fasting insulin as the outcome variables. Pearson correlation coefficients for vitamins E and C in relation to rank SI were r = 0.07 (P = 0.01) and r = 0.07 (P = 0.02), respectively. After adjustment for total energy and BMI these associations were no longer statistically significant and did not differ between ethnic groups. Results were similar when vitamins E and C were combined in categories of low and high antioxidant intake. Models replicated with log of fasting insulin as the outcome variable also did not produce significant associations with vitamins E or C. Thus, these cross-sectional analyses do not support the hypothesis of improved SI with increased intake of vitamins E and C.

Do ethnic differences in dietary cation intake explain ethnic differences in hypertension prevalence? Results from a cross-sectional analysis

PURPOSE

To better understand how the magnitude of the association between ethnicity and hypertension is affected by ethnic differences in dietary cation intake, we describe differences in dietary cation intakes and prevalence of hypertension across four ethnic groups (African-Americans, European-Americans, Mexican-Americans, and Puerto Ricans). We also assess the cross-sectional association between: (i) hypertension and self-reported dietary intakes of sodium, potassium, and calcium for each ethnic group; and (ii) ethnicity and hypertension before and after adjustment for dietary cation intakes.

METHODS

Data from the Second National Health and Nutrition Examination Survey (1976-1980) and the Hispanic Health and Nutrition Examination Survey (1982-1984) were analyzed. Multiple logistic regression was used to estimate odds ratio (OR) for hypertension for each ethnic group, with adjustment for age, body mass index (BMI), and diabetes status. Comparisons were made to assess whether the magnitude for the ethnicity ORs changed when the three nutrient variables were entered into the model.

RESULTS

Mexican-American and Puerto Rican men and women showed clinically and statistically significantly higher mean intakes of the three cations than did African-American men and women, who reported clinically and statistically significantly lower mean intakes of sodium, potassium, and calcium than did European-American men and women. Mean dietary intakes of potassium and calcium were higher for normotensives than for hypertensives among all ethnic groups, except African-American and Mexican-American women. In multivariate modeling, stark differences in ORs for hypertension persisted across ethnic groups despite inclusion of the nutrient variables.

CONCLUSION

In this cross-sectional study, adjustment for dietary cation intakes did not alter the magnitude of the ethnic differences in prevalence of hypertension.

Relative weight and mortality in U.S. blacks and whites: findings from representative national population samples

PURPOSE

To examine the impact of relative weight on mortality in black and white men and women.

METHODS

Two representative national populations samples were used: the NHANES-I Epidemiologic Follow-up Study (NHEFS), and the National Health Interview Survey (NHIS). The principal analysis focused on 13,242 participants in the NHEFS and 114,954 in the NHIS. Minimum mortality was estimated from both categorical analysis and a logistic model.

RESULTS

Minimum mortality ranged from a body mass index (BMI) of 25 to 32 kg/m2. The model-estimated BMI of minimum mortality for NHEFS was 27.1 (24.8-29.4, 95% CI), 26.8 (24.7-28.9, 95% CI), 24.8 (23.8-25.9, 95% CI) and 24.3 (23.2-25.4, 95% CI); for black men, black women, white men and white women, respectively, whereas for NHIS the corresponding values were 30.2 (24.8-35.6, 95% CI) 26.4 (24.2-28.7, 95% CI), 27.1 (25.5-28.7, 95% CI), and 25.6 (24.2-27.0, 95% CI). In all groups the shape of the relative risk curve was virtually identical and a broad range of BMI values in the middle of the distribution was associated with low relative mortality risk. Averaging the results from both surveys, the observed BMI of minimum risk was 3.1 kg/m2 higher in black men and 1.5 kg/m2 higher in black women than in their white counterparts; when adjusted for covariates these differences were only of borderline statistical significance, however.

CONCLUSIONS

Because of the wide range of BMI values associated with low risk, and the consistency of the point of the up-turn in risk, group specific definitions of optimal values do not appear to be warranted.

Do sociodemographics and economic status predict risks for type II diabetes in African Americans?

The prevalence of type II diabetes and the metabolic characteristics in high-risk African Americans were examined to determine whether certain socioeconomic and demographic characteristics (SED) increase the risk for type II diabetes in this population. Study participants were high-risk African Americans between the ages of 25 and 64 years. Glucose tolerance status was assessed and questionnaires were completed to obtain information regarding SED, hypertension, and physical activity. The majority of patients had normal glucose tolerance; undiagnosed type II diabetes was identified in 36 of 164 patients. Questionnaire data revealed that, in highly selected African Americans at risk for type II diabetes, there was a higher rate of obesity, prior gestational diabetes, and undiagnosed type II diabetes despite higher educational and income levels and greater access to health care and recreational facilities. Findings indicate that African Americans may be at higher risk for type II diabetes, regardless of socioeconomic status, due to genetic inheritance and other unknown environmental determinants. Further studies are needed to characterize SED and metabolic profiles that confer a high risk for type II diabetes in this population.

Social class and race disparities in premature stroke mortality among men in North Carolina

The purpose of this work was to examine the association between social class and premature stroke mortality among blacks and whites. For black men and white men in North Carolina, aged 35-54 years, mortality data from vital statistics files and population data from Census Public Use Microdata Sample files were matched according to social class for the years 1984-1993. Four categories of social class were defined based upon a two-dimensional classification scheme of occupations. For each category of social class, race-specific age-adjusted stroke mortality rates were calculated, and race-specific prevalences of income, wealth, education, unemployment, and disability were estimated. Women were excluded because comparable information on social class was not available from the mortality and population data sources. For both black men and white men, the highest rates of premature stroke mortality were observed among the lowest social classes. The rate ratios (RR) between the lowest and highest social class were 2.8 for black men and 2.3 for white men. Within each social class, black men had substantially higher rates of premature stroke mortality than white men (black-to-white RR ranged from 4.0 to 4.9). Among both black men and white men, the highest social class consistently had the most favorable levels of income, wealth, education, and employment. The inverse association between social class and stroke mortality for both black men and white men supports the need for stroke prevention efforts that address the structural inequalities in economic and social conditions.

Patterns of comorbidity and mortality risk in blacks and whites

Comorbidity, the co-existence of multiple chronic conditions in a single individual, has been shown to modify the prognosis of disease states. To estimate disease burdens within and among racial subpopulations of the United States, we examined cross-sectional patterns of comorbidity and their impact on survival using data from the NHANES-1 Epidemiologic Follow-up Study (NHEFS). We considered the occurrence of four cardiovascular conditions: stroke, coronary heart disease, hypertension and diabetes. We summarize the joint occurrence of these four conditions using these different methodologies: the number of conditions occurring in each individual and two summaries that weight the conditions according to their prognostic significance. Using all three methodologies, we found an excess burden of chronic disease in black women as compared with white women. Black men had an excess burden compared to white men for the first two methodologies. However, when we model the relationship of the joint occurrence of the conditions to subsequent mortality, black men and white men are seen to have a similar burden. This similarity of black and white men is due to an interaction between race and prevalent stroke in men that we hypothesize may be due to the small number of black men available for study. Given the apparent conditioning effect of co-existing diseases, it is evident that estimation of disease burdens among groups that differ in terms of health status, in particular among U.S. blacks and whites, requires accounting for the occurrence of multiple chronic diseases. Using either the number of conditions or the prognosis weighted summary, we demonstrated a higher burden of the conditions considered in blacks that in whites in a sample of the U.S. population.

Secular trends in coronary atherosclerosis--analysis in patients with valvular regurgitation

BACKGROUND

Between 1980 and 1989, mortality due to coronary artery disease decreased considerably in the United States, suggesting a possible decrease in the prevalence of coronary atherosclerosis. We examined this possibility in patients with valvular regurgitation who, often in the absence of angina, underwent coronary angiography before valve-replacement surgery.

METHODS

We studied 601 patients with isolated, nonischemic valvular regurgitation who were operated on between 1980 and 1989 and who had undergone preoperative coronary angiography. From the angiograms we determined the prevalence of clinically significant coronary artery disease and of multivessel disease, assessed the mean degree of stenosis, and analyzed the trends in the data over the years of the study.

RESULTS

The prevalence of coronary artery disease (35 percent in 1980-1981, 37 percent in 1982-1983, 34 percent in 1984-1985, 37 percent in 1986-1987, and 35 percent in 1988-1989; P = 0.97) did not change significantly during the study period. We found no significant change in the prevalence of multivessel disease (24 percent in 1980-1981 and 23 percent in 1988-1989, P = 0.99) or in the mean ( +/- SD) degree of stenosis (11 +/- 13 percent in 1980-1981 and 13 +/- 14 percent in 1988-1989, P = 0.07). When these measures of coronary atherosclerosis were adjusted for age and sex, there were still no significant changes over time (P = 0.39 for the prevalence of coronary artery disease, P = 0.81 for that of multivessel disease, and P = 0.57 for the mean degree of stenosis). The patients' mean total cholesterol level decreased from 219 +/- 48 mg per deciliter (5.66 +/- 1.24 mmol per liter) to 206 +/- 44 mg per deciliter (5.33 +/- 1.14 mmol per liter) between 1980 and 1989 (P = 0.04).

CONCLUSIONS

From 1980 to 1989, no significant change was observed in angiographic measures of coronary atherosclerosis in patients with nonischemic valvular regurgitation, in contrast to the marked decrease in mortality due to coronary disease in the general population. These findings suggest that the well-documented reduction in mortality due to coronary disease may not be due to a reduction in the prevalence of coronary atherosclerosis.

Life changes, locus of control and metabolic syndrome precursors in adolescents and young adults: a three-year follow-up

The relations between life changes, locus of control and changes in the parameters of the metabolic syndrome were examined. A three-year follow-up study of 671 randomly selected, healthy adolescents and young adults was used. Somatic parameters measured both at the baseline and the follow-up were serum insulin, serum HDL chol, serum triglyceride, SBP and BMI. Locus of control was measured with the Nowicki-Strickland locus of control scale and subjects were asked about life changes that they had faced during the follow-up period. Results showed that, in women, there were significant main effects for life changes in predicting (high) somatic risk level, whereas, in men, an opposite association was found. In addition, locus of control had a moderating effect on the life change-metabolic parameters relation, i.e. most of the life changes predicted a lower level of somatic risk in subjects with an external rather than internal locus of control. Results question the universal applicability of beneficial health effects of internal locus of control. It was suggested that accumulation of life changes might contribute, in interaction with locus of control, to the early development of the metabolic syndrome.

Coronary heart disease risk factors in black and white patients with non-insulin-dependent diabetes mellitus

OBJECTIVE

To determine possible racial differences in risk factors for coronary heart disease (CHD) in black and white patients with noninsulin-dependent diabetes mellitus (NIDDM).

METHODS

Study of risk factors for coronary heart disease among 308 subjects who met the WHO criteria for NIDDM.

RESULTS

Both black and white patients were found to have a high prevalence of hypertension, obesity, low high density lipoprotein (HDL) cholesterol, low leisure-time physical activity levels, and an atherogenic dietary profile. Black males were more likely to have hypertension, reported a greater intake of dietary cholesterol, and had lower triglycerides, higher HDL cholesterol levels, a lower CHOL/HDL ratio, and a lower waist to hip ratio (WHR) than white males. Black females had higher mean arterial and diastolic blood pressures, had lower triglycerides, higher HDL cholesterol, a lower CHOL/HDL ratio, a higher subscapular/triceps ratio and lower reported leisure-time energy expenditure compared to white females. There were no racial differences found for obesity level.

CONCLUSION

Our results indicate that racial differences in CHD risk factors exist among black and white patients with NIDDM. The complex genetic, sociocultural and environmental interactions involving CHD risk factors that contribute to the development of CHD may eventually provide clues to the etiology of the disease.

Diabetes mellitus, race, and socioeconomic status. A population-based study

To identify factors associated with diabetes mellitus and to determine whether racial differences in these factors, especially socioeconomic status, explain the high prevalence of diabetes among African-Americans, we performed a cross-sectional study using a population-based, representative sample from three US communities. The participants comprised 975 white and 418 African-American adults, aged 35 to 54 years. The main outcome variable was the presence of diabetes defined by either self-report or abnormal results on the oral glucose tolerance test (serum glucose level > 10.0 mmol/L (180 mg/dL) 1 hour after 50-g oral glucose dose). Compared to their white counterparts, African-American participants were more overweight, displayed greater central adiposity, and had lower socioeconomic status. Diabetes was over twice as prevalent among African-Americans (10.3%) as compared to whites (4.6%; odds ratio (OR) = 2.38; 95% confidence interval (95% CI): 1.50, 3.75; P = 0.0001). After adjustments for racial differences in age, socioeconomic status, overweight, and central adiposity, African-Americans remained over twice as likely to have diabetes compared to whites (OR = 2.35; 95% CI: 1.49, 3.73; P = 0.0003). The excess prevalence of diabetes in African-Americans was greatest in individuals of low socioeconomic status (OR = 4.09) and least among individuals of high socioeconomic status (OR = 1.90; P < 0.001 for trend). Racial differences in obesity and socioeconomic status do not appear to explain fully the higher prevalence of diabetes among African-Americans. African-American race seems to be a strong, independent risk factor for diabetes, especially among individuals of low socioeconomic status.

Baseline dietary intake and physical activity of Japanese American men in relation to glucose tolerance at 5-year follow-up

Japanese American men (n = 124), with normal glucose tolerance (NGT, n = 69) or impaired glucose tolerance (IGT, n = 55) at baseline, were studied for effects of baseline dietary intake and physical activity on glucose tolerance at baseline and at 5-year follow-up. At baseline, both NGT and IGT men with positive family history of diabetes (FH) showed high intakes of animal fat and protein, but only the NGT men countered this with high levels of energy expenditure. In the total sample at 5-year follow-up, 2-hour plasma glucose was significantly related to intake of animal fat (AF), partial correlation r = 0.32, P < 0.001, adjusted for total energy intake, age, self-reported health, body mass index, FH, and baseline glucose tolerance category. Energy expenditure (EE) was not related to 5-year 2-hour plasma glucose in the total sample, but displayed a relationship with 5-year 2-hour plasma glucose in those IGT (r = -0.27, P < 0.05), but not in those NGT at baseline, and in those with positive FH (r = -0.33, P < 0.05), but not in those with negative FH. Additionally, AF showed a relationship to 5-year 2-hour plasma glucose only for those in the lowest (r = 0.37, P < 0.05) and middle (r = 0.33, P < 0.05) tertiles, but not in the highest tertile of EE. For baseline IGT men, 5-year 2-hour plasma glucose was related to "high vs. low risk" categories of AF intake and EE, but only in men with a positive FH (AF ≥ 25 vs. < 25 g/day: 180.1 ± 38.6 vs. 143.6 ± 39.7 mg/dl, P = 0.048; EE ≤ 2,000 kcal/week vs. > 2,000 kcal/week, 189.9 ± 39.2 vs. 150.8 ± 37.4 mg/dl, P = 0.028; with risk categories combined, i.e., both high, mixed, both low: 192.0 ± 41.3, 165.4 ± 28.4, 139.4 ± 40.9 mg/dl, P = 0.045, linear trend, P = 0.014). Thus, high AF intake and low EE may have long-range detrimental effects on glucose tolerance, especially for those with IGT and positive FH. © 1996 Wiley-Liss, Inc.

Diabetes in the elderly

Diabetes affects at least 20% of the population over the age of 65. Half of these patients are unaware that they have the disease. Diabetes in middle-aged subjects is characterized by an impairment in glucose induced insulin release, increased fasting hepatic glucose output and resistance to insulin mediated glucose disposal. In contrast, diabetes in the elderly is primarily associated with insulin deficiency. The presentation of diabetes in the aged is often non-specific. The elderly have an increased frequency of complications from diabetes. They are particularly susceptible to hypoglycaemia, because of reduced awareness of hypoglycaemic warning symptoms and altered release of counterregulatory hormones. Although no data are yet available from randomized controlled trials, there is abundant epidemiological evidence to suggest that adequate control of blood glucose can be expected to reduce the risk of long-term complications. A team approach is ideal for the management of the elderly patient with diabetes. Little data is available on which to base a diet and exercise prescription for elderly patients. Gliclazide appears to be the sulphonylurea of choice in the aged because it is associated with a lower frequency of hypoglycaemic reactions. Urine glucose testing is unreliable, and capillary glucose monitoring is preferred. Fructosamine may prove to be superior to haemoglobin A1C for monitoring long-term control.

Age at diagnosis of non-insulin-dependent diabetes mellitus in southern Iran

To obtain an estimate of the age at onset of non-insulin-dependent diabetes mellitus in southern Iran, the medical records of the confirmed diabetic patients who attended the diabetes and endocrine clinics in southern Iran from March 1984 to February 1993 were reviewed. The case records of 2566 patients, in whom non-insulin-dependent diabetes mellitus was considered most probable, and who were resident in southern Iran at the time of diagnosis, were studied; they included 1176 (45.8%) men and 1390 (54.2%) women. The age at diagnosis of the disease in men ranged between 18 and 82 years with a mean of 45.6 +/- 11.4 (+/- SD) years, and in women, between 15 and 83 with a mean of 44.3 +/- 12.2 (+/- SD) years. There was no statistically significant sex-related difference in the mean age at diagnosis of non-insulin-dependent diabetes mellitus in these patients. Sex-specific rates showed a female to male ratio of 1.25 to 1. Age-specific rates indicated that non-insulin-dependent diabetes mellitus was most often diagnosed before age 55 and most commonly in the forties.

Serum 25-hydroxyvitamin D3 levels decreased in impaired glucose tolerance and diabetes mellitus

A cross-sectional survey was carried out in a New Zealand Polynesian and Caucasian workforce of 5677 staff aged 40-64 years to determine whether serum concentrations of 25-hydroxyvitamin D3 are altered in people with newly diagnosed diabetes mellitus and impaired glucose tolerance (IGT). Serum 25-hydroxyvitamin D3 concentration was significantly lower in newly detected cases with diabetes and IGT (n = 238) compared with controls individually matched by sex, age (+/- 2 years), ethnicity, and date of interview (mean (S.D.): 69 (31) vs. 76 (34) nmol/l; P = 0.0016). Among controls, serum concentrations were significantly lower in Maori (mean (S.E.) = 65 (5) nmol/l; P = 0.0013) and Pacific Islanders (59 (4) nmol/l; P = 0.0001) compared with Europeans (82 (3) nmol/l), after adjusting for age, sex, and time of year. We conclude that diabetes and IGT are associated with low serum concentrations of 25-hydroxyvitamin D3 and that low concentrations of this hormone in New Zealand Polynesians may partly explain their increased prevalence of diabetes/IGT compared with Europeans.

Incidence and predictors of diabetes in Japanese-American men. The Honolulu Heart Program

Reports on the incidence and predictors of diabetes in minority populations are infrequent. The 6-year cumulative incidence of diabetes between 1965 and 1974 was estimated among 7210 Japanese-American men aged 45 to 68 years who were enrolled in the Honolulu Heart Program and were free of clinically recognized diabetes at baseline. The incidence of "possible" diabetes (based on history, medication, or hospital diagnosis) was 12.8% and the incidence of "probable" diabetes (based on diabetic medication) was 5.7%. Estimates of incidence in subjects with a nonfasting glucose concentration less than 225 mg/dL 1 hour after a 50-g load were 9.7 and 4.0%, respectively. Multivariate adjusted odds ratios (ORs) for probable diabetes in all subjects comparing the upper quintile with the lower four quintiles combined for continuous variables indicated statistically significant direct associations with body mass index (OR, 1.69; 95% confidence interval (CI), 1.31 to 2.18), 1-hour postchallenge glucose level (OR, 5.79; 95% CI, 4.58 to 7.33), triglyceride levels (OR, 1.47; 95% CI, 1.14 to 1.91), systolic blood pressure (OR, 1.36; 95% CI, 1.05 to 1.76), and parental history of diabetes (OR, 1.73; 95% CI, 1.29 to 2.33), and an inverse association with physical activity (OR, 0.49; 95% CI, 0.34 to 0.72), using logistic regression models including these variables as well as age, subscapular/triceps skinfold ratio, and hematocrit simultaneously. Associations were similar but slightly weaker in men with glucose levels less than 225 mg/dL and in those who remained free of cardiovascular disease. When older men (55 to 68 years old) were compared with younger (45 to 54 years old) men, associations among the older group were stronger for body mass index, physical activity, and systolic blood pressure and they were weaker for glucose levels, triglyceride values, and parental diabetes. Results suggest that body mass index, physical inactivity, glucose level, and parental diabetes appear to be independent risk factors for diabetes, while triglyceride and systolic blood pressure levels may be markers for an adverse cardiovascular risk factor profile associated with diabetes and may reflect an insulin resistance syndrome.