Type 2 diabetes in octogenarians is associated with decreased low molecular weight adiponectin.
BACKGROUND
Adiponectin circulates in the blood in three different multimer isoforms, of which the high molecular weight form (HMW) is presumed to mediate insulin sensitivity. We examined whether adiponectin oligomer distribution is associated with aging and type 2 diabetes (T2D) in octogenarians without characteristic features of metabolic syndrome.


METHODS
The study included 154 octogenarians (58 men, 96 women), 24 normoglycemic middle-aged controls (11 men, 13 women; mean age 44 years), and 33 middle-aged individuals (14 men, 19 women; mean age 55 years) with T2D. Based on oral glucose tolerance test 62 octogenarians had normal, 63 impaired glucose tolerance, and 29 octogenarians had newly detected T2D. Serum adiponectin multimer isoforms were measured after overnight fast by enzyme-linked immunosorbent assays.


RESULTS
Compared to the normoglycemic middle-aged control group, male normoglycemic octogenarians revealed significantly higher total adiponectin and all adiponectin isoforms. The same was true for females with the exception of low molecular weight (LMW) adiponectin, which was not statistically higher in octogenarians. Male and female octogenarians with T2D had significantly higher levels of total, HMW, and middle molecular weight (MMW) adiponectin, but not LMW adiponectin, than middle-aged individuals with T2D. Female, but not male, octogenarians revealed significantly lower total adiponectin than normoglycemic octogenarians. Compared with normoglycemic octogenarians, male and female octogenarians with T2D were characterized by significantly lower LMW adiponectin. In male and female octogenarians, total adiponectin and all multimer isoforms were directly correlated with HDL cholesterol. LMW adiponectin in octogenarians of both sexes was inversely correlated with glucose level at 2-hour oral glucose tolerance test.


CONCLUSIONS
Serum levels of total adiponectin as well as its HMW and MMW isoforms were significantly higher in octogenarians with normoglycemia or T2D than in corresponding middle-aged control groups. In male and female octogenarians without metabolic syndrome, T2D was associated with lower LMW adiponectin, while the HMW and MMW isoforms were not statistically different.
Graessler
Juergen
J
Department of Internal Medicine III, Carl Gustav Carus Medical School, University of Technology, Dresden, Germany. Graessler@uniklinikum-dresden.de
Gruber
Matthias
M
Radke
Rolf-Bernd
RB
Kopprasch
Steffi
S
Schwarz
Peter E H
PE
Kamke
Wolfram
W
Bornstein
Stefan R
SR
Fischer
Sabine
S
D052242:Adiponectin / Q000097:blood* / Q000737:chemistry / Q000378:metabolism; D000367:Age Factors; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000886:Anthropometry; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000032:analysis; D016022:Case-Control Studies; D016001:Confidence Intervals; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D015577:Geriatric Assessment; D005951:Glucose Tolerance Test; D006801:Humans; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D012016:Reference Values; D018570:Risk Assessment; D012737:Sex Factors
D052242:Adiponectin; D015415:Biomarkers; D001786:Blood Glucose