Serum insulin-like growth factor-I concentration is associated with leukocyte telomere length in a population-based cohort of elderly men.
BACKGROUND
Both leukocyte telomere length and IGF-I are associated with the aging process. A previous in vitro study suggested that IGF-I may modulate telomerase activity in white blood cells, but little is known whether these two systems interact in vivo.


METHODS
Leukocyte telomere length was determined using a quantitative PCR assay in 2744 elderly men (mean age 75.5 yr, range 69-81 yr) included in the population-based Osteoporotic Fractures in Men-Sweden study. Serum IGF-I concentration was measured using RIA.


RESULTS
Subjects with a leukocyte telomere length in the lowest tertile group had lower serum IGF-I concentration than subjects in the two tertile groups with longer telomere lengths (P = 0.005). Logistic regression analyses showed that a higher serum IGF-I concentration was associated with a significantly reduced risk of having a leukocyte telomere length in the lowest tertile group and also after adjustment for multiple covariates (P < 0.01). Multivariate linear regression analyses demonstrated that tertile of leukocyte telomere length was positively, whereas age was negatively, associated with serum IGF-I concentration in elderly men.


CONCLUSIONS
In this large population-based, cross-sectional study, leukocyte telomere length was positively associated with serum IGF-I concentration in elderly men. The mechanisms underlying the association between serum IGF-I concentration and leukocyte telomere length remain to be determined.
Center for Bone Research, Department of Internal Medicine, Sahlgrenska Academy, University of Gothenburg, SE-413 45 Gothenburg, Sweden.
Sofia
S
Movérare-Skrtic
Johan
J
Svensson
Magnus K
MK
Karlsson
Eric
E
Orwoll
Osten
O
Ljunggren
Dan
D
Mellström
Claes
C
Ohlsson
D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D001823:Body Composition / Q000235:genetics; D015331:Cohort Studies; D004247:DNA / Q000235:genetics / Q000648:ultrastructure; D003920:Diabetes Mellitus / Q000235:genetics; D006801:Humans; D006973:Hypertension / Q000235:genetics; D007334:Insulin-Like Growth Factor I / Q000235:genetics* / Q000378:metabolism*; D007962:Leukocytes / Q000648:ultrastructure*; D008019:Life Style; D008297:Male; D016017:Odds Ratio; D011153:Population; D019098:Telomerase / Q000235:genetics; D016615:Telomere / Q000235:genetics* / Q000648:ultrastructure*
D007334:Insulin-Like Growth Factor I; D004247:DNA; D019098:Telomerase