The endocrinology of familial longevity : time series analyses of different hormonal axes and their interrelationships

Maintenance and repair is of key importance for the proper functioning of cells, tissues, and integrated physiology. We hypothesize that the balance between investments in growth, development, and reproduction versus maintenance and repair is regulated by the brain. Specifically (the interplay of) hormones of the different hypothalamic-pituitary-target gland axes seem to be key regulators in constantly adjusting this balance to its optimal state. This thesis describes the associations between familial longevity and hormones of different hypothalamic-pituitary-target gland axes. In Chapter 2, the question is addressed whether circulating insulin-like growth factor 1 (IGF‐1) axis parameters associate with old age survival and functional status in nonagenarians from the LLS. In Chapter 3, we use growth hormone (GH) concentrations measured every 10 min over 24 h to derive and compare GH secretion parameters between offspring of long-lived families and their partners. In Chapter 4, we investigate the association between hypothalamic-pituitary-gonadal axis parameters and familial longevity. In Chapter 5, we use 24-h time series data of pituitary hormones to investigate how changes in the different hormonal axes are correlated with each other over time. In Chapter 6, we determine the circadian rhythm of bone turnover markers in healthy older subjects. LUMC / Geneeskund