title: The natural history of impaired glucose tolerance in the Pima Indians.
abstract: Among 384 Pima Indians with impaired glucose tolerance according to World Health Organization criteria who were followed for 1.6 to 11.5 years (median, 3.3), non-insulin-dependent diabetes mellitus (NIDDM) developed in 118 (31 percent), glucose tolerance remained impaired in 100 (26 percent), and glucose tolerance returned to normal in 166 (43 percent). The cumulative incidence of NIDDM was 25 and 61 percent at 5 and 10 years, respectively. The risk of development of diabetes was 6.3 times (95 percent confidence interval, 3.8 to 10.6) as high as in a normoglycemic control group (n = 752). Variables predicting deterioration to NIDDM were age up to the age of 40, after which increasing age had a beneficial effect; higher plasma glucose levels during fasting and after carbohydrate loading; and higher serum insulin levels after fasting and lower levels after carbohydrate loading, suggesting that insulin resistance and decreased beta-cell responsiveness are important determinants of the clinical outcome of impaired glucose tolerance. Obese subjects had 2.9 times (95 percent confidence interval, 2.0 to 10.9) the incidence of NIDDM as the nonobese. Obesity was not, however, predictive of progression to NIDDM after an adjustment for plasma glucose and serum insulin levels. We conclude that in this population approximately one fourth of subjects with impaired glucose tolerance have NIDDM at five years and two thirds at 10 years (approximately one third revert to normal) and that age and plasma glucose and insulin levels are the best predictors of clinical outcome.
authors.affiliation: Diabetes and Arthritis Epidemiology Section, National Institute of Diabetes and Digestive and Kidney Diseases, Phoenix, Ariz.
authors.forename: M F
authors.initials: MF
authors.lastname: Saad
authors.forename: W C
authors.initials: WC
authors.lastname: Knowler
authors.forename: D J
authors.initials: DJ
authors.lastname: Pettitt
authors.forename: R G
authors.initials: RG
authors.lastname: Nelson
authors.forename: D M
authors.initials: DM
authors.lastname: Mott
authors.forename: P H
authors.initials: PH
authors.lastname: Bennett
mesh_terms: D000328:Adult; D000367:Age Factors; D001130:Arizona; D001786:Blood Glucose / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D008297:Male; D009765:Obesity / Q000150:complications; D012307:Risk Factors; D013997:Time Factors
chemical_list: D001786:Blood Glucose; D007328:Insulin