Metabolic and hormonal contributors to survival in the participants of the Mataró Ageing Study at 8 years follow-up

Abstract

Objective: Ageing is a physiological process that may be influenced by genetic factors as well as metabolic and hormonal determinants. The aim was to describe metabolic and hormonal factors related to survival in the cohort of non-institutionalized people aged >70 years old of the Mataró Ageing Study.

Design and methods: 313 individuals were included and followed-up during 8 years. Metabolic syndrome (MS) parameters by International Diabetes Federation and ATP-III as well as hormonal factors (TSH, free-T4, growth hormone, IGF-I, ghrelin, cortisol, dehydroepiandrosterone -DHEA-, DHEAs, testosterone, SHBG, estradiol, estrone, cortisol/DHEA and cortisol/DHEAs) were studied and their relationship with survival was assessed.

Results: At 8 year of follow-up, 96 out of 313 subjects (30·7%) died. No association between MS and its components and survival was found. However, when abdominal perimeter was analyzed according to distribution in quartiles and categorized by gender, the lowest and highest quartile showed higher mortality (P = 0·009; waist circumference (WC) between 98-102 cm in men and 95-102 cm in women were associated to lower mortality). In men, IGF-I, estrone, cortisol/DHEA ratio and cortisol/DHEAs ratio were lower in survivors, and in women, growth hormone and ghrelin were higher in survivors and cortisol/DHEAs ratio was lower. When Cox regression was performed for survival analysis of the whole cohort (adjusting by age, gender, tobacco consumption and WC, cortisol (B = 0·036, P = 0·033), estrone (B = 0·014, P = 0·004) and cortisol/DHEA ratio (B = 0·018, P = 0·008) were significantly associated to mortality. Sequential adjustments including additionally in the model Lawton scale, MiniNutritional Assessment and MCE showed significant association to estrone (P = 0·018).

Conclusions: Waist circumference in a U-shaped relationship, together with hormonal factors (adrenal steroids and somatotropic axis) influenced survival in individuals participating in Mataró Ageing Study.