Normal insulin sensitivity in lean offspring of obese parents.
OBJECTIVE
Offspring of diabetic or hypertensive patients are insulin resistant at a prediabetic/prehypertensive stage. We tested the hypothesis that insulin action may be impaired in the offspring of obese nondiabetic parents.


METHODS
Twenty-one lean offspring of nonobese subjects [(OL) 22 +/- 3 years of age] were matched to 23 lean offspring of obese subjects (OOb) by gender distribution, age, BMI, and waist circumference. Anthropometry, oral glucose tolerance, in vivo insulin sensitivity [by a euglycemic insulin clamp (6 pmol/min per kilogram(FFM); where FFM represents fat-free mass)], and thermogenesis (by indirect calorimetry) were measured in each subject. The study subjects were from a population of 267 nuclear families (one offspring and both his/her parents) in which there was statistically significant (chi2 = 30.2, p = 0.001) concordance of BMI between parents and offspring.


RESULTS
In comparing OOb with OL, no statistically significant difference or trend toward a difference was detected in fasting plasma glucose and insulin concentrations, glucose and insulin responses to oral glucose, insulin sensitivity [metabolism value = 45 +/- 12 (OOb) vs. 47 +/- 17 micro mol/min per kilogram(FFM) (OL)], insulin-induced inhibition of protein and lipid oxidation, stimulation of glucose oxidation and nonoxidative glucose disposal, respiratory quotient, resting energy expenditure, and glucose-induced thermogenesis.


CONCLUSIONS
The metabolic similarity between lean offspring of obese parents and those of nonobese parents suggests that insulin resistance and its correlates are not co-inherited with the predisposition to develop obesity.
Lazarin
Mary A C T
MA
Department of Internal Medicine, School of Medical Sciences, State University of Campinas, UNICAMP, São Paulo, Brazil.
Bennini
João R
JR
Pereira
Carlos L C
CL
Astiarraga
Brenno D
BD
Ferrannini
Ele
E
Muscelli
Elza
E
D000328:Adult; D001786:Blood Glucose / Q000032:analysis; D001823:Body Composition; D001824:Body Constitution; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D005260:Female; D015309:Glucose Clamp Technique; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D007333:Insulin Resistance / Q000235:genetics*; D008297:Male; D009765:Obesity / Q000209:etiology / Q000235:genetics*; D010290:Parents
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin