Familial resemblance for glucose and insulin metabolism indices derived from an intravenous glucose tolerance test in Blacks and Whites of the HERITAGE Family Study.

Type 2 diabetes mellitus (T2DM), characterized by hyperglycemia, is a complex disease primarily caused by impairment in insulin sensitivity (SI) and insulin secretion. While a strong genetic component for T2DM is well established, there are few reports on racial differences in the magnitude of the genetic effects of T2DM and indices of glucose and insulin metabolism. We report here on the familial resemblance for traits related to glucose metabolism at pre-exercise training levels in 492 members from 99 sedentary White families and 259 members from 108 Black families participating in the multicenter HERITAGE Family Study. All these traits were obtained from the frequently sampled intravenous glucose tolerance test (IVGTT). They include glucose disappearance index (Kg), an overall index for glucose tolerance, acute insulin response to glucose (AIR(Glucose)) which is an index for insulin secretion, and those derived from the minimal model including SI and the disposition index (DI). DI, derived as the product of SI and AIR(Glucose), is a measure of the activity of the B-cells adjusted for insulin resistance. After adjustment for age, sex, and body mass index, the maximal heritability estimates in Blacks (Whites) are 48+/-14% (25+/-8%) for Kg, 44+/-14% (46+/-8%) for AIR(Glucose), 38+/-12% (44+/-8%) for SI and 32+/-14% (24+/-8%) for DI. Interestingly, Blacks have higher heritability for overall glucose tolerance than Whites but there is no race difference in heritability estimates for insulin sensitivity or insulin secretion.

Senile dementia of the Alzheimer's type: an important risk factor for serious falls.

In a longitudinal study of senile dementia and healthy aging, the occurrence of serious falls was examined in participants with senile dementia of the Alzheimer's type (SDAT) (n = 44) and in cognitively healthy elderly control participants (n = 56) over a 4-year period. Falls occurred in 36% of SDAT individuals versus 11% of controls. The higher frequency of falls in demented participants was not explained by greater neurologic deficit nor by increased drug use compared with controls. However, males with SDAT who reported falls, had higher mean blood pressures and were more likely to be medicated than males with SDAT who did not fall. These differences were not observed in women. Falls in SDAT participants were associated with an increased rate of institutionalization. SDAT is an important risk factor for serious falls, and falls are associated with loss of independence in demented patients.

Race, socioeconomic status, and prostatic cancer.

Using mortality and incidence data from Alameda County, California, this study attempted to determine whether the higher occurrence rate of prostatic cancer among black men as compared with whites in the United States might be explained by racial differences in factors associated with socioeconomic status. Each death or case of prostatic cancer was assigned to a social class based on census tract of residence, and rates by race and socioeconomic status were computed. Comparison of age-specific mortality and incidence rates by socioeconomic status reveals no gradient in either whites or blacks. The higher risk for blacks holds up at almost every age and socioeconomic level. However, the racial differences are less pronounced for incidence than for mortality. Racial differences in the occurrrence of deaths appearing in Part II of the death certificate are also examined.