title: Sex hormone binding globulin levels across the adult lifespan in women--the role of body mass index and fasting insulin.
abstract: SHBG is a major carrier of androgens. In men, SHBG levels increase with age, while in women data are scant. There is evidence that body mass index (BMI) and fasting insulin influence SHBG concentration. Since low SHBG levels are predictors of insulin resistance and diabetes, understanding the relationship of SHBG with age, insulin, and BMI is important to gain insight into the role of SHBG as a cardiovascular risk factor in women. Differences in SHBG across adult life span and their relationship with insulin and BMI were evaluated in a representative cohort of 616 Italian women free of diabetes and not on hormone replacement therapy enrolled in the InCHIANTI Study. The relationship of SHBG with age, BMI, and fasting insulin levels was analyzed using linear regression and by loess smoother. Serum SHBG levels showed a U-shaped trajectory with age, declining from the 2nd to the 6th decade of life and increasing after the 6th decade (p<0.0001). Age-related trends for BMI and fasting insulin mirrored the trend observed for SHBG. After adjusting for fasting insulin, the relationship between log (SHBG) and age square was attenuated (beta coefficient from 0.00044 to 0.00039) and was further reduced after adjustment for BMI (from 0.00039 to 0.00028). SHBG levels show an age-related U-shaped trajectory. These changes mirror the age-related changes in BMI and fasting insulin, suggesting that BMI and insulin negatively influence SHBG concentration.
authors.affiliation: Department of Internal Medicine and Biomedical Sciences, Section of Geriatrics, School of Endocrinology, University of Parma, Parma, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Maggio
authors.forename: F
authors.initials: F
authors.lastname: Lauretani
authors.forename: S
authors.initials: S
authors.lastname: Basaria
authors.forename: G P
authors.initials: GP
authors.lastname: Ceda
authors.forename: S
authors.initials: S
authors.lastname: Bandinelli
authors.forename: E J
authors.initials: EJ
authors.lastname: Metter
authors.forename: A J
authors.initials: AJ
authors.lastname: Bos
authors.forename: C
authors.initials: C
authors.lastname: Ruggiero
authors.forename: G
authors.initials: G
authors.lastname: Ceresini
authors.forename: G
authors.initials: G
authors.lastname: Paolisso
authors.forename: A
authors.initials: A
authors.lastname: Artoni
authors.forename: G
authors.initials: G
authors.lastname: Valenti
authors.forename: J M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: L
authors.initials: L
authors.lastname: Ferrucci
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D015992:Body Mass Index; D005215:Fasting; D005260:Female; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D012044:Regression Analysis; D012738:Sex Hormone-Binding Globulin / Q000378:metabolism*; D055815:Young Adult
chemical_list: D007328:Insulin; D012738:Sex Hormone-Binding Globulin
references.citation: Clin Endocrinol (Oxf). 1974 Jan;3(1):69-96
references.pmid: 4134992
references.citation: J Clin Endocrinol Metab. 1993 Jul;77(1):56-60
references.pmid: 8325960
references.citation: J Clin Endocrinol Metab. 1993 Feb;76(2):283-7
references.pmid: 8432770
references.citation: Menopause. 2004 Mar-Apr;11(2):159-66
references.pmid: 15021445
references.citation: Int J Obes. 1991 Jul;15(7):471-8
references.pmid: 1894424
references.citation: J Clin Endocrinol Metab. 2005 Jul;90(7):3847-53
references.pmid: 15827095
references.citation: J Steroid Biochem Mol Biol. 1991;40(4-6):841-9
references.pmid: 1958579
references.citation: Acta Endocrinol (Copenh). 1984 Jul;106(3):428-32
references.pmid: 6540022
references.citation: Nutr Cancer. 2000;38(2):158-62
references.pmid: 11525592
references.citation: Circulation. 2003 Oct 7;108(14):1688-93
references.pmid: 12975257
references.citation: J Am Geriatr Soc. 2000 Dec;48(12):1618-25
references.pmid: 11129752
references.citation: J Clin Endocrinol Metab. 2001 Feb;86(2):724-31
references.pmid: 11158037
references.citation: Maturitas. 1995 Feb;21(2):103-13
references.pmid: 7752947
references.citation: Eur J Endocrinol. 1998 Aug;139(2):178-83
references.pmid: 9724073
references.citation: JAMA. 2006 Mar 15;295(11):1288-99
references.pmid: 16537739
references.citation: J Endocrinol. 1990 Feb;124(2):R1-3
references.pmid: 1690256
references.citation: Clin Lab. 2005;51(11-12):625-32
references.pmid: 16329620
references.citation: Atherosclerosis. 2002 Apr;161(2):455-62
references.pmid: 11888531
references.citation: Circulation. 2005 Mar 15;111(10):1242-9
references.pmid: 15769764
references.citation: Am J Epidemiol. 2006 May 15;163(10):938-49
references.pmid: 16641311
references.citation: Metabolism. 1997 Jan;46(1):5-9
references.pmid: 9005961
references.citation: J Gerontol A Biol Sci Med Sci. 2004 May;59(5):466-72
references.pmid: 15123757
references.citation: J Clin Endocrinol Metab. 2000 Aug;85(8):2832-8
references.pmid: 10946891
references.citation: J Clin Endocrinol Metab. 1988 Sep;67(3):460-4
references.pmid: 2842359