Biomedical subjects

B D Mitchell

Publications and source records attributed to B D Mitchell.

At least 91 records · Page 5Linked to original sources

PubMed1992

Eight-year incidence of hypertension in Mexican-Americans and non-Hispanic whites. The San Antonio Heart Study.

The prevalence of hypertension has been reported to be lower in Mexican-Americans (MAs) than in non-Hispanic whites (NHWs). This finding is paradoxical since, compared to NHWs, MAs are generally more obese, and generally have a higher prevalence of non-insulin-dependent diabetes mellitus (NIDDM), both of which are risk factors for hypertension. Thus far, no data exist on the incidence of hypertension in MAs. We therefore determined the 8-year incidence of hypertension (defined as a diastolic blood pressure greater than or equal to 95 mm Hg or current treatment with antihypertensive medications) in 1462 subjects (867 MAs and 595 NHWs) who were normotensive at baseline and who subsequently participated in the 8-year follow-up of the San Antonio Heart Study, a population-based study of diabetes and cardiovascular risk factors. Hypertension developed in 79 MAs (9.1%) and 55 NHWs (9.2%). The age-adjusted odds ratio (OR) for ethnicity (MA/NHW) was 0.83 (95% CI = 0.48, 1.44) in men and 1.25 (95% CI = 0.76, 2.04) in women. After adjusting for age, gender, body mass index, NIDDM, and level of educational attainment using multiple logistic regression, Mexican-Americans had an incidence of hypertension similar to non-Hispanic white (OR = 0.80, 95% CI = 0.52, 1.22). The similar incidence of hypertension in MAs is in striking contrast to the markedly increased incidence of NIDDM in this ethnic group relative to non-Hispanic whites. The cause of the relative protection from hypertension in MAs is unknown.

Adult↗

PubMed1992

Genetic and environmental determinants of type II diabetes in Mexico City and San Antonio.

To study genetic and environmental determinants of non-insulin-dependent (type II) diabetes, we compared a random sample of 35- to 64-yr-old Mexican-American men and women living in several low-income barrio neighborhoods of San Antonio to similarly aged Mexicans living in a low-income colonia of Mexico City (Colonia Liberales). A total of 1138 Mexican Americans, representing 64.3% of the original sample, and 646 Mexicans, representing 69.2% of the original sample, participated in the survey. Diabetes was diagnosed using World Health Organization criteria. Genetic susceptibility to type II diabetes was inferred from the percentage of Native American genetic admixture as estimated from skin reflectance measurements. The prevalence of diabetes was 36% higher among San Antonio Mexican Americans than among Mexicans in Mexico City; this difference was highly statistically significant (age- and sex-adjusted prevalence ratio 1.36, P = 0.006). This excess was observed despite the fact that genetic susceptibility, as inferred from the admixture estimates, was similar in the two cities. On the other hand, Mexicans were somewhat leaner as measured by body mass index and skin folds. Mexican women consumed fewer total calories than Mexican-American women, but there was no difference in the caloric intake of men. Mexico City residents ate less fat (18-19% of total calories vs. 31-32% in San Antonio, P less than 0.001), more carbohydrate (64-65 vs. 49%, P less than 0.001), and performed more physical activity than San Antonio Mexican Americans. Mexicans appeared to consume more refined sugar than Mexican Americans.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Prospective analysis of the insulin-resistance syndrome (syndrome X).

Many studies have shown that hyperinsulinemia and/or insulin resistance are related to various metabolic and physiological disorders including hypertension, dyslipidemia, and non-insulin-dependent diabetes mellitus. This syndrome has been termed Syndrome X. An important limitation of previous studies has been that they all have been cross sectional, and thus the presence of insulin resistance could be a consequence of the underlying metabolic disorders rather than its cause. We examined the relationship of fasting insulin concentration (as an indicator of insulin resistance) to the incidence of multiple metabolic abnormalities in the 8-yr follow-up of the cohort enrolled in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease in Mexican Americans and non-Hispanic whites. In univariate analyses, fasting insulin was related to the incidence of the following conditions: hypertension, decreased high-density lipoprotein cholesterol concentration, increased triglyceride concentration, and non-insulin-dependent diabetes mellitus. Hyperinsulinemia was not related to increased low-density lipoprotein or total cholesterol concentration. In multivariate analyses, after adjustment for obesity and body fat distribution, fasting insulin continued to be significantly related to the incidence of decreased high-density lipoprotein cholesterol and increased triglyceride concentrations and to the incidence of non-insulin-dependent diabetes mellitus. Baseline insulin concentrations were higher in subjects who subsequently developed multiple metabolic disorders. These results were not attributable to differences in baseline obesity and were similar in Mexican Americans and non-Hispanic whites. These results support the existence of a metabolic syndrome and the relationship of that syndrome to multiple metabolic disorders by showing that elevations of insulin concentration precede the development of numerous metabolic disorders.

Adult↗

PubMed1992

Greater effect of glycemia on incidence of hypertension in women than in men.

OBJECTIVE: In subjects with NIDDM, diabetic women have a greater relative excess of CHD relative to nondiabetic women than do diabetic men relative to nondiabetic men. This excess in diabetic women is explained partially by the particularly atherogenic pattern of lipoproteins in this group. We hypothesize that diabetic women also may have a higher incidence of hypertension than diabetic men. RESEARCH DESIGN AND METHODS: We examined the effect of NIDDM and IGT relative to NGT on the incidence of hypertension separately in men (n = 844) and women (n = 618) in the 8-yr follow-up of the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. RESULTS: Women had a greater risk of hypertension with worsening glucose tolerance (RR NIDDM/NGT = 2.65 and RR IGT/NGT = 1.94) compared with men (RR NIDDM/NGT = 1.61 and RR IGT/NGT = 0.91). Controlling for other possible confounding variables such as age, obesity, body fat distribution, and fasting insulin concentration did not alter the interaction of sex and glycemia on incidence of hypertension. CONCLUSIONS: The especially increased risk of hypertension in women with abnormal glucose tolerance may explain partly the high risk of CHD in this group.

Blood Glucose↗

PubMed1992

Dietary protein intake is not correlated with clinical proteinuria in NIDDM.

OBJECTIVE: To determine whether dietary protein intake is correlated with clinical proteinuria in subjects with non-insulin-dependent diabetes mellitus (NIDDM). RESEARCH DESIGN AND METHODS: Cross-sectional analysis of data obtained from the San Antonio Heart Study, a population-based survey of diabetes and cardiovascular risk factors. Subjects were enrolled in two phases: phase 1 between 1979 and 1982 and phase 2 between 1984 and 1988. This study was based on 376 NIDDM subjects who had both urinalysis and complete dietary protein intake information available. Dietary protein intake was measured by 24-h dietary recall in phase 1 and by food-frequency questionnaire in phase 2. An early-morning spot urine was obtained from study subjects. Clinical proteinuria was defined as greater than or equal to 1 on Ames Albustix test. RESULTS: In phase 1, the subjects with negative or trace proteinuria had a mean protein intake of 79.9 g/day compared with 72.1 g/day for subjects with greater than or equal to 1 proteinuria. In phase 2, the mean protein intake was 72.2 g/day in the negative/trace group and 65.3 g/day in the greater than or equal to 1 proteinuria group. In multivariate analysis, adjusting for age, sex, ethnicity, systolic blood pressure, and 2-h blood glucose, we were again unable to detect a significant correlation between dietary protein intake and clinical proteinuria. CONCLUSIONS: These data do not support the hypothesis that high-protein intake is a risk factor for clinical proteinuria in NIDDM subjects. Therefore, any recommendation for protein restriction in the diets of NIDDM subjects, before the development of NIDDM-related nephropathy, must be made with caution.

Adult↗

PubMed1992

Impact of associated conditions on glycemic control of NIDDM patients.

OBJECTIVE: To assess the impact of associated conditions (obesity, dyslipidemia, and hypertension) on the glycemic control of non-insulin-dependent diabetes mellitus (NIDDM) patients under home-life conditions. RESEARCH DESIGN AND METHODS: We analyzed the metabolic data of 271 NIDDM patients (89% Mexican American) screened in a population-based survey (the San Antonio Heart Study). RESULTS: Obesity was present in 77% of the patients, hypertension in 23%, hypertriglyceridemia (serum triglycerides greater than 2.9 mM) in 23%, and hypercholesterolemia (serum total cholesterol greater than 6.5 mM) in 14%. Forty percent of the patients had two or more comorbid conditions. With the use of a multiple linear regression model, which was adjusted for age, sex, ethnicity, distribution of body fat (waist-hip ratio), plasma insulin, and treatment (of both diabetes and hypertension), we found that the presence of higher serum triglyceride concentrations was associated with significantly higher plasma glucose levels both in the fasting state (1.4 mM, P less than 0.001) and 2 h after an oral glucose load (1.2 mM, P = 0.003). The presence of obesity, hypertension, or high serum cholesterol levels was not associated with significant changes in glycemic control. When the entire group was stratified by diabetes treatment (untreated n = 89, diet n = 75, oral agents n = 82, insulin n = 25) and after adjusting for age, sex, ethnicity, and waist-hip ratio, only fasting and 2-h plasma glucose and insulin concentrations were significantly different across treatment groups, with diet and oral agents being associated with higher fasting (P less than 0.001) and postglucose (P less than 0.005) plasma glucose levels and lower plasma insulin concentrations (P less than 0.005) compared with newly diagnosed patients. Neither serum lipids nor blood pressure differed across treatment. CONCLUSIONS: In NIDDM patients under home-life conditions, higher serum triglycerides are associated with higher fasting and postglucose hyperglycemia regardless of antidiabetic treatment. The presence of obesity, hypertension, or high serum cholesterol levels is not associated with significant changes in glycemic control.

Blood Glucose↗

PubMed1992

Does glycemic control of type II diabetes suffice to control diabetic dyslipidemia? A community perspective.

OBJECTIVE: To assess the extent to which glycemic control by itself results in satisfactory control of diabetic dyslipidemia. RESEARCH DESIGN AND METHODS: A population-based case series consisting of 386 Mexican Americans and 94 non-Hispanic whites with non-insulin-dependent (type II) diabetes was studied. All subjects answered questions about their medical history and care received and underwent a standardized oral glucose tolerance test and measurements of fasting serum lipid and lipoprotein concentrations. Three definitions of dyslipidemia were used: total cholesterol greater than 6.20 mM (240 mg/dl), triglyceride greater than 2.82 mM (250 mg/dl), and high-density lipoprotein cholesterol less than 0.90 mM (35 mg/dl). RESULTS: Despite having removed subjects receiving lipid-lowering drugs, diabetic subjects who had been previously diagnosed and were under medical care exhibited a lower prevalence of hypertriglyceridemia than those who were newly diagnosed at the time of their survey visit, suggesting that conventional management was associated with a reduced frequency of this dyslipidemia. Among previously diagnosed cases, the prevalence of dyslipidemia rose with worsening glycemic control but there was little association with type of therapy (diet only, oral agents, or insulin) or frequency of physician visits. In general, the prevalence of dyslipidemia in diabetic subjects remained higher than in nondiabetic subjects, despite hypoglycemic therapy. CONCLUSIONS: The results suggest that glycemic control by itself does not suffice to control diabetic dyslipidemia and that significant numbers of diabetic subjects will need direct lipid management. Clinical trials are urgently needed to define the optimum management strategy for diabetic dyslipidemia.

Adult↗

PubMed1992

Recent developments in the epidemiology of diabetes in the Americas.

The prevalence of diabetes recorded in population surveys in the American region varies from < 1% (rural Mapuche Indians aged 20 years and over, Chile) to almost 50% (Pima Indians aged 20 years and over, United States of America). The prevalence of non-insulin-dependent diabetes mellitus (NIDDM) was approximately 2.5 times higher among Mexican Americans than in non-Hispanic white Americans. In the Mexican Americans, prevalence followed a sociocultural gradient: 16% in low-income barrios, about 10% in middle-income neighbourhoods and 5% in high-income suburbs in San Antonio, Texas. Data from the Hispanic Health and Nutrition Examination Survey indicate prevalence of diabetes in the age range 45-74 years of 24% for Mexican Americans, 26% for Puerto Ricans and 16% for Cuban Americans, compared to 12% for non-Hispanic whites. Figures for a low-income district of Mexico City show a 36% lower prevalence than for Mexican Americans in the USA. Prevalence in Brazil is approximately 7% in subjects aged 30-69 years. Black Americans have a relatively high prevalence of NIDDM, though not as high as the Mexican Americans. There is evidence that complications of diabetes may vary between populations, and that they may be particularly severe in Mexican Americans, and higher in black than in white Americans. The extent to which these differences relate to access to health care and treatment remains to be clarified.

Adolescent↗

PubMed1992

Public health significance of upper body adiposity for non-insulin dependent diabetes mellitus in Mexican Americans.

An unfavourable body fat distribution has been associated with an increased prevalence and incidence of non-insulin dependent diabetes mellitus (NIDDM). The potential utility of assessing body fat distribution in diabetes screening, however, has not been assessed. We compared the impact of upper body fat distribution (assessed by the waist-to-hip ratio (WHR)) and body mass index (BMI) and NIDDM using the population attributable risk approach of Levin in 1965 Mexican Americans from the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. The population attributable risk percentage (PAR%) was 52.0% for WHR compared to 43.4% for body mass index. After stratification by BMI, women with a high WHR had a PAR% of approximately 50% and men had a PAR% of 28-58%. For any given cutpoint (e.g. the 10th percentile, 20th percentile, etc.) of WHR used to screen for NIDDM, WHR had both a higher sensitivity and a lower false positive rate than the corresponding cutpoint of BMI. To evaluate the relative contribution of WHR in identifying prevalent cases of NIDDM, multiple logistic regression analyses were performed, and the number of subjects identified as being in the top 20% of the risk score distribution was compared using a model that included WHR and a model that included BMI. In men, BMI did not increase the sensitivity in detecting NIDDM subjects once age was accounted for; WHR increased the sensitivity only slightly. In women, sensitivity was enhanced modestly using both measures, although WHR again was the more sensitive method. These data suggest that WHR is a better single screening measure for NIDDM than BMI.

Adipose Tissue↗

PubMed1991

Hyperinsulinaemia: the key feature of a cardiovascular and metabolic syndrome.

In a population-based survey of 2,930 subjects, prevalence rates for obesity, Type 2 (non-insulin-dependent) diabetes mellitus, impaired glucose tolerance, hypertension, hypertriglyceridaemia, and hypercholesterolaemia were 54.3, 9.3, 11.1, 9.8, 10.3 and 9.2%, respectively. The prevalence, however, of each of these conditions in its isolated form (free of the other five) was 29.0% for obesity, 1.3% for Type 2 diabetes, 1.8% for impaired glucose tolerance, 1.5% for hypertension, 1.0% for hypertriglyceridaemia, and 1.7% for hypercholesterolaemia. Two-by-two associations were even rarer. The large differences in prevalence between isolated and mixed forms indicate a major overlap among the six disorders in multiple combinations. In the isolated form, each condition was characterized by hyperinsulinaemia (both fasting and 2 h after oral glucose), suggesting the presence of insulin resistance. In addition, in any isolated condition most of the variables categorising other members of the sextet were still significantly altered in comparison with 1,049 normal subjects. In the whole of the subjects who presented with one or another disorder (1,881 of 2,930 or 64%), marked fasting and post-glucose hyperinsulinaemia was associated with higher body mass index, waist:hip ratio, fasting and post-glucose glycaemia, systolic and diastolic blood pressure, serum triglycerides and total cholesterol levels, and with lower HDL-cholesterol concentrations (all p less than 0.001). We conclude that (1) insulin sensitivity, glucose tolerance, blood pressure, body fat mass and distribution, and serum lipids are a network of mutually interrelated functions; and (2) an insulin resistance syndrome underlies each and all of the six disorders carrying an increased risk of coronary artery disease.

Adult↗

PubMed1991

High prevalence of angina pectoris in Mexican-American men. A population with reduced risk of myocardial infarction.

Mexican-American men experience lower rates of cardiovascular mortality and have a lower prevalence of nonfatal myocardial infarction than do non-Hispanic white men. To see if this ethnic difference exists for other cardiovascular end points, we compared the prevalence of angina pectoris, as assessed by the Rose Angina Questionnaire, between Mexican Americans (n = 3272) and non-Hispanic whites (n = 1848) examined in the San Antonio Heart Study, a population-based survey of cardiovascular disease and diabetes conducted in San Antonio, Texas, between 1979 and 1988. Contrary to our expectations, angina prevalence was approximately twice as high in Mexican Americans as in non-Hispanic whites, with age-adjusted odds ratios of 2.01 (95% confidence interval (CI), 1.13 to 3.58; P = .02) in men and 1.84 (95% CI, 1.26 to 2.70; P = .001) in women. After controlling for age, body mass index, diabetes status, cigarette smoking, and educational level by logistic regression analysis, angina prevalence remained statistically associated with Mexican American ethnicity in men, but not women. There was little ethnic difference in the proportion of Mexican-American and non-Hispanic white subjects who reported nonspecific chest pain (chest pain not meeting the Rose criteria), suggesting that the ethnic difference in angina prevalence was not an artifact of reporting bias. This was further supported by the fact that the conventional cardiovascular risk factors were more strongly associated with angina prevalence in Mexican Americans than in non-Hispanic whites. These data suggest that Mexican-American men experience high rates of angina despite low rates of myocardial infarction. Future studies should investigate ethnic factors that may have differential effects on the various manifestations of coronary heart disease.

Adult↗

PubMed1991

Greater influence of central distribution of adipose tissue on incidence of non-insulin-dependent diabetes in women than men.

Many studies have shown an increased prevalence of non-insulin-dependent diabetes (NIDDM) in individuals with an unfavorable body fat distribution, but there are still relatively few prospective studies on this topic. We present data on the 8-y incidence of NIDDM in Mexican-American men and women according to their degree of central adiposity, measured by the ratio of subscapular to triceps skinfold thicknesses. Subjects were initially enrolled in the San Antonio Heart Study, a population-based study of diabetes in Mexican Americans and non-Hispanic whites. Sixteen of 254 initially nondiabetic men and 27 of 366 initially nondiabetic women developed diabetes. Central adiposity was more strongly associated with diabetes incidence in women than in men. After adjustment for overall adiposity (measured by body mass index), women in the highest and in the middle tertile of centrality had a significantly higher risk of diabetes than did women in the lowest tertile [odds ratio (OR) = 10.70, P = 0.008, highest vs lowest tertile, and OR = 8.55, P = 0.032, middle vs lowest tertile; for men OR = 3.70 and OR = 1.38, respectively].

Adipose Tissue↗

PubMed1991

Obesity in Mexican American subgroups: findings from the San Antonio Heart Study.

This study describes the prevalence of overweight in 2013 Mexican Americans and 928 non-Hispanic whites, aged 25-65 y, who participated in phase 2 of the San Antonio Heart Study, 1984-1988, and examines differences in overall obesity and body fat distribution among diverse Mexican American subgroups defined by neighborhood, socioeconomic status (SES), and assimilation to mainstream US society. Prevalence of overweight was greater in Mexican Americans than in non-Hispanic whites, and the ethnic difference was greater in women than in men. In Mexican Americans the effects of SES and assimilation on overall obesity and body fat distribution differed by sex group. In men SES and cultural assimilation were associated with less favorable body fat distribution. In women SES and assimilation were associated with lower overall obesity and more favorable body fat distribution. Interventions to reduce obesity in Mexican Americans should take these subgroup differences into account.

Acculturation↗

PubMed1991

Predictors of obesity in Mexican Americans.

Excess body weight is a risk factor for morbidity and mortality in several studies. The etiology of obesity is, however, poorly understood. We examined the ability of selected behavioral variables to predict weight gain (greater than 6.8 kg) in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease in Mexican Americans and non-Hispanic whites. However, we were unable to confirm an effect of dietary variables or level of physical exercise in predicting future obesity in Mexican Americans. To some degree this may be because of the imprecision of the 24-h-dietary-recall technique and the dietary behavior and exercise questionnaires.

Body Mass Index↗

PubMed1991

High blood pressure and insulin resistance: influence of ethnic background.

Hyperinsulinaemia links non-insulin dependent diabetes (NIDDM), obesity, and hypertension, each an insulin-resistant state in its own right. Insulin resistance predicts the occurrence of NIDDM, and plays a major role in its pathogenesis. We tested the hypothesis that hyperinsulinaemia may also predict hypertension in a sample (n = 2905) of the mixed population of San Antonio, in which hyperinsulinaemia and NIDDM are more prevalent among Mexican-Americans than non-Hispanic whites. Whilst in the whole sample the hypertensives had significantly (P less than 0.001) higher plasma insulin concentrations than the normotensives, high blood pressure was significantly (P less than 0.01) more frequent among non-Hispanic whites than Mexican-Americans regardless of diabetes status. After adjusting for factors (age, sex, body mass, and body fat distribution) known to affect insulin levels, a direct relationship between post-glucose plasma insulin concentrations and prevalence of hypertension was still present in both ethnic groups. In Mexican-Americans, however, the standardized prevalence of hypertension was significantly (P less than 0.001) lower at any given insulin concentration. Post-glucose plasma glucose levels also were directly related to hypertension prevalence in both groups; again, the regression line was shifted downward and, furthermore, less steep (P less than 0.02) in Mexican-Americans, suggesting relative protection against the negative effect of hyperglycaemia on blood pressure. Dyslipidaemia (higher total cholesterol and triglyceride, and lower HDL-cholesterol concentrations) was strongly associated with hyperinsulinaemia and blood pressure in both ethnic groups. After adjusting for plasma insulin, only hypertriglyceridaemia was associated with high blood pressure, with no inter-ethnic difference.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Myocardial infarction in Mexican-Americans and non-Hispanic whites. The San Antonio Heart Study.

Mexican-American men experience reduced cardiovascular mortality compared with non-Hispanic white men. There is no corresponding ethnic difference in cardiovascular mortality in women. The difference in men could result either from a lower incidence of cardiovascular disease or a lower case fatality rate among Mexican-Americans. Although the incidence of cardiovascular disease in Mexican-Americans is unknown, we have collected data on prevalence of myocardial infarction in 5,148 individuals examined in the San Antonio Heart Study, a population-based survey of cardiovascular disease conducted between 1979 and 1988 in Mexican-Americans and non-Hispanic whites aged 25-64 years. Myocardial infarction was assessed by Minnesota-coded electrocardiograms and by a self-reported history of a physician-diagnosed heart attack. For both end points, the age-adjusted prevalence of myocardial infarction was lower in Mexican-American men than in non-Hispanic white men. After adjustment for age and diabetes status (present/absent), the odds of a myocardial infarction, as defined by either criterion, was approximately one third lower in Mexican-American men than in non-Hispanic white men (p = 0.06). In women, the prevalence of both myocardial infarction end points was slightly higher in Mexican-Americans than in non-Hispanic whites, although neither of these differences was significant. Although the ethnic differences in prevalence in this study were not statistically significant, their pattern parallels the pattern in the mortality due to cardiovascular diseases. Therefore, the results support the hypothesis that the reduced cardiovascular mortality rate observed in Mexican-American men reflects a lower incidence of myocardial infarction rather than a reduced case fatality rate because the latter would result in a higher prevalence.

Adult↗

PubMed1991

Increased incidence of type II diabetes mellitus in Mexican Americans.

OBJECTIVE: To determine whether Mexican Americans have an increased incidence of non-insulin-dependent (type II) diabetes mellitus relative to non-Hispanic whites. Currently, no study has reported on the incidence of this disorder in Mexican Americans. RESEARCH DESIGN AND METHODS: We determined the 8-yr incidence of type II diabetes in 617 Mexican Americans and 306 non-Hispanic whites who participated in the San Antonio Heart Study, a population-based study of diabetes and cardiovascular disease. Forty Mexican Americans (6.5%) and 6 non-Hispanic whites (2%) developed type II diabetes, as defined by World Health Organization criteria. The age-adjusted ethnic odds ratio (OR; Mexican Americans/non-Hispanic whites) for diabetes incidence was 8.13 (95% confidence interval [C1] 1.10-59.9) in men and 3.62 (95% CI 1.37-9.55) in women. We adjusted for age, sex, ethnicity, body mass index, and level of educational attainment with multiple logistic regression analyses. RESULTS: Mexican Americans continued to show a statistically significant increase in diabetes incidence (OR 2.72, 95% CI 1.02-7.28). Obesity and age were also positively related to diabetes incidence in this analysis (P less than 0.001). In addition, subjects with at least some college education had a lower incidence of diabetes than those with less than a high school education (OR 0.51, 95% CI 0.26-0.99). CONCLUSIONS: The incidence of type II diabetes in Mexican Americans is greater than in non-Hispanic whites, a difference that is not explained by ethnic differences in obesity, age, or level of educational attainment.

Adult↗

PubMed1991

Genetic and environmental determinants of type II diabetes in Mexican Americans. Is there a "descending limb" to the modernization/diabetes relationship?

Evidence from migrant population studies and secular trend data indicates that environmental factors play a role in the etiology of non-insulin-dependent (type II) diabetes. These environmental factors appear to be concomitants of the process whereby traditional populations become "modernized" or "westernized" and include increased intake of total calories, fat, and sucrose, decreased intake of total and complex carbohydrates, including fiber, and decreased physical exercise. There also appears to be a "postmodernization" process, which we have characterized as the "descending limb of the curve." In Mexican Americans in San Antonio, the prevalence of type II diabetes declines with acculturation to the values, attitudes, and behaviors of "postmodernized" American society. However, examination of the dietary and exercise concomitants of this process revealed a mixed picture. There was some suggestion that Mexican-American women, although not men, had entered onto the descending limb of the curve. However, Native American genetic admixture in Mexican Americans also covaried with affluence and acculturation in such a way that the declining prevalence of diabetes could as easily be due to genetic factors as to environmental factors. The "pancreatic exhaustion" theory holds that resistance to insulin action is a principal lesion leading to hypersecretion of insulin, hyperinsulinemia, and eventual islet cell failure and clinical diabetes. This theory predicts that prediabetic subjects will be hyperinsulinemic. In conformity with this theory, we have shown that subgroups of the Mexican-American population, defined on the basis of family history of diabetes, who would be expected a priori to be enriched with prediabetic subjects, are hyperinsulinemic as predicted.(ABSTRACT TRUNCATED AT 250 WORDS)

Diabetes Mellitus↗