Age and glucose tolerance in healthy subjects.
An important and still controversial issue is the role played by the aging process itself in the metabolic alterations observed in aged people. We previously reported that a group of normal elderly people exhibited glucose disposal comparable to that of young controls. In the present study we investigated the effect of age on beta-cell secretion, by analyzing C-peptide measurements. Ten elderly men (E, 70 +/- 2 years) with normal oral glucose test and ten young subjects (Y, 27 +/- 1 years) with matching ideal body weight formed the study group. They were studied under highly dynamic conditions by means of a 0.3 g/kg i.v. glucose tolerance test. Fasting glucose and insulin were not different in the two groups (Y: 87 +/- 2 mg/di, E: 88 +/- 3, p greater than 0.1; Y: 50 +/- 7 pM, E: 36 +/- 7, p greater than 0.05). Glucose-insulin data set was analyzed by means of the minimal model of glucose disappearance which provided two parameters for every individual, yielding a quantitative description of glucose utilization: i.e., SI, the index of insulin sensitivity, and SG, the fractional glucose disappearance at basal insulin (glucose effectiveness). Both parameters were unaltered by age (SI = Y: 6.30 +/- 0.41 10(-4)min-1/(microU/ml), E: 7.11 +/- 0.72, p greater than 0.1; SG = Y: 0.020 +/- 0.003 min-1, E: 0.019 +/- 0.002, p greater than 0.1). C-peptide time course in elderly people was systematically lower than in the control group (basal levels: Y: 252 +/- 36 pM, E: 129 +/- 17, p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
Beccaro
F
F
Geriatric Hospital, Padova, Italy.
Pacini
G
G
Valerio
A
A
Nosadini
R
R
Crepaldi
G
G
D000284:Administration, Oral; D000368:Aged; D000375:Aging / Q000378:metabolism*; D001786:Blood Glucose / Q000032:analysis; D002096:C-Peptide / Q000097:blood; D005947:Glucose / Q000378:metabolism*; D005951:Glucose Tolerance Test / Q000379:methods; D006801:Humans; D007275:Injections, Intravenous; D007328:Insulin / Q000097:blood; D008297:Male; D008875:Middle Aged
D001786:Blood Glucose; D002096:C-Peptide; D007328:Insulin; D005947:Glucose