Partitioning the Variability of Fasting Plasma Glucose
Levels in Pedigrees. Genetic and Environmental Factors
Boehnke M, Moll PP, Kottke BA, Weidman WH
American Journal of Epidemiology, 125(4):679-689 (1987)
Abstract
Fasting plasma glucose measurements made in 1972-1977 on normoglycemic individuals
in three-generation Caucasian pedigrees from Rochester, Minnesota were analyzed. The
authors determined the contributions of polygenic loci and environmental factors to fasting
plasma glucose variability in these pedigrees. To that end, fasting plasma glucose
measurements were normalized by an inverse normal scores transformation and then
regressed separately for males and females on measured concomitants including age, body
mass index (weight/height2), season of measurement, sex hormone use, and diuretic use.
The authors found that 27.7% of the variability in normalized fasting plasma glucose in
these pedigrees is explained by these measured concomitants. Subsequent variance
components analysis suggested that unmeasured polygenic loci and unmeasured shared
environmental factors together account for at least an additional 36.7% of the variability in
normalized fasting plasma glucose, with genes alone accounting for at least 27.3%. These
results are consistent with the known familiality of diabetes, for which fasting plasma
glucose level is an important predictor. Further, these familial factors provide an
explanation for at least half the variability in normalized fasting plasma glucose which
remains after regression on known concomitants.
Variance component linkage analysis