A screening neurologic examination capable of detecting distal symmetric (sensory) neuropathy in a large population-based study of non-insulin-dependent diabetes mellitus in San Luis Valley, Colorado, in 1984-1986 is described and validated. The examination, completed in 279 diabetics and 577 controls, had 90% agreement with a standard neurologic examination completed on a subsample of 38 patients. Independent validation of neuropathy status was obtained with the Optacon tactile (vibration) stimulator. Mean, age-adjusted vibration threshold was significantly greater in those with neuropathy than in those without. The subtests of the examination most sensitive in detecting neuropathy were a combination of a positive history of neuropathy symptoms and decreased or absent deep tendon reflexes in both ankles. Age-adjusted prevalence of neuropathy in controls, those with impaired glucose tolerance, and diabetics was 3.9%, 11.2%, and 25.8%, respectively. Prevalence odds ratios were 3.5 and 10.6 for the presence of neuropathy in persons with impaired glucose tolerance and diabetes, respectively, compared with persons with normal glucose tolerance. Neuropathy was significantly associated with age, duration of diabetes, male sex, and glycemic control, but not with Anglo/Hispanic status.

The San Luis Valley Diabetes Study was undertaken to determine the prevalence, risk factors, and complications of non-insulin-dependent diabetes mellitus in Hispanics and Anglos (non-Hispanic whites), using a geographically based case-control design. The study was conducted in two southern Colorado counties that include 43.6% Hispanic and 54.9% Anglo persons. Medical practice records were reviewed to identify medically diagnosed diabetics. Controls without diabetes were identified by a two-stage random sample of households. Diabetics (n = 343) and controls (n = 607) attended a clinic where an oral glucose tolerance test or current hypoglycemic therapy confirmed or diagnosed non-insulin-dependent diabetes mellitus. The age-adjusted prevalence of confirmed non-insulin-dependent diabetes mellitus was 21/1,000 in Anglo males and 44/1,000 in Hispanic males, accounting for non-response. For Anglo females, the prevalence was 13/1,000 compared with 62/1,000 for Hispanic females, accounting for nonresponse. Previously undiagnosed non-insulin-dependent diabetes mellitus was also higher among Hispanics. There was a 2.1-fold excess of confirmed non-insulin-dependent diabetes mellitus among Hispanic males and a 4.8-fold excess among Hispanic females, consistent with the excess non-insulin-dependent diabetes mellitus among Hispanics reported from comparable studies. Non-insulin-dependent diabetes mellitus is a major chronic disease problem for persons of Hispanic ethnicity.

There are two possible sources of bias in the assessment of family history of diabetes: 1) a person with diabetes may be more likely to report a diabetic relative than a nondiabetic person would be, and 2) relatives of individuals with diabetes may be more likely to be tested for diabetes than relatives of nondiabetic individuals. We conducted a study on a subsample of families of subjects in the San Luis Valley Diabetes Study to examine these issues. A sample of 5 White and 5 Hispanic subjects (probands) with diabetic glucose tolerance tests and the same number with normal glucose tolerance were selected. The 20 probands all provided contact information on their 227 primary family members. Ninety-two percent of the family members had interviews completed by themselves or, if deceased, by surrogates other than the proband. Family members were asked by telephone if they had ever been tested for diabetes, when they had been most recently tested, why they had been tested, and if they had ever been told they had diabetes. The results showed that study subjects accurately reported family history of diabetes, because there were no discrepancies between proband and family reports. A positive family history of diabetes was associated with increased reported screening in Hispanics, but a similar effect in White families was not seen. Women were also more likely to report being screened than men regardless of whether there was a positive family history of diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiovascular risk factor patterns were examined cross-sectionally in 856 Hispanic and Anglo subjects aged 20-74 years enrolled in the population-based San Luis Valley Diabetes Study of Colorado. Risk factor levels and prevalence were compared for 279 individuals with non-insulin-dependent diabetes mellitus, 89 with impaired glucose tolerance, and 488 with normal glucose tolerance. Sex-specific comparisons of continuous risk factors were made by diabetic status and ethnicity, adjusting for age using two-way analysis of covariance; similar comparisons of discrete variables were made using logistic regression. A number of vascular, metabolic, lipid, obesity-related, family history, and life-style risk factors for cardiovascular disease were examined. In general, biologic risk factors tended to be more strongly associated with diabetic status, while life-style risk factors varied more by ethnicity. Age-adjusted levels of systolic and diastolic blood pressure, hypertension history, triglyceride, and body mass index were lowest among normal subjects, intermediate for those with impaired glucose tolerance, and highest in subjects with non-insulin-dependent diabetes mellitus, while the trend was reversed for high density lipoprotein (HDL) cholesterol and its subfractions. Hispanics had lower serum uric acid levels and greater central obesity than Anglos; they were less likely to have a Type A personality, less physically active at work, and more likely to be a current smoker than Anglos. Hispanic males had a lower body mass index and a higher HDL cholesterol level than Anglo males. These results indicate that an adverse cardiovascular risk factor pattern is present not only in subjects with non-insulin-dependent diabetes mellitus but also in subjects with impaired glucose tolerance who are at increased risk of developing diabetes. This suggests that an adverse risk factor pattern may develop concurrently with or prior to the onset of impaired glucose tolerance. Future prospective studies will help to clarify the temporal sequence involved in the development of adverse cardiovascular risk factor patterns and impaired glucose tolerance.

The goal of this article was to examine the differences in the rates of microvascular complications of non-insulin-dependent diabetes mellitus (NIDDM) in Hispanic and non-Hispanic white subjects. This was a geographically based case-control study where prevalent cases of NIDDM were identified in medical records. Subjects attended a 4-h clinic to confirm NIDDM diagnosis and assess complication end points. Retinopathy was defined by stereofundus photographs. Distal symmetric neuropathy was determined by standardized clinical examination. Nephropathy was indicated by serum creatinine level, urine protein-creatinine ratio, and urine albumin concentration. This study consisted of 279 NIDDM subjects confirmed by oral glucose tolerance test and World Health Organization criteria aged 20-74 yr (187 Hispanic and 92 non-Hispanic white subjects). Duration-adjusted prevalence of retinopathy was significantly higher in non-Hispanic white subjects (54.1 per 100, 95% confidence interval [CI] 44.4-63.7) than in Hispanics (41.8 per 100, 95% CI 34.8-48.8). This excess occurred only in non-Hispanic white subjects with background retinopathy but not in those with more severe retinopathy. Hispanics and non-Hispanic white subjects did not differ significantly for the prevalence of neuropathy (31.6 per 100 in non-Hispanic white subjects and 26.3 per 100 in Hispanics) or nephropathy by any measure. There were no significant differences in duration of diabetes or mean glycohemoglobin levels between ethnic groups. Microvascular complications of NIDDM are not in excess among Colorado Hispanics, and retinopathy may be somewhat more common in non-Hispanic white people.