Vitamin D, thyroid hormones and muscle mass influence natural killer (NK) innate immunity in healthy nonagenarians and centenarians

Abstract

Increasing evidence has demonstrated that the immune system closely interacts with other physiological systems, whose communications are mediated by circulating cytokines and hormones. The aim of our study was to test whether the number and cytolytic activity of NK cells in a group of relatively healthy Italian nonagenarians and centenarians were affected by the modifications of endocrine, metabolic and functional parameters that occur during ageing. Because of the extreme age of the study population, a cross-sectional analysis was performed. This study revealed that the group of oldest subjects with the highest number of NK cells and the best preserved cytolytic function also presented a preserved metabolism of thyroid hormones and vitamin D and integrity of muscle mass. In fact, the NK cell number and/or cytolytic activity of healthy subjects > 90 years old was positively associated with serum levels of vitamin D, while T3, FT4, i-PTH hormones and lean body mass were associated only with NK cell number. In conclusion, our results stress the paramount importance of nutritional evaluation in the clinical assessment of elderly people.

Vitamin D Status Affects Serum Metabolomic Profiles in Pregnant Adolescents

“…59 In these pregnant adolescents, vitamin D sufficiency was associated with lower concentrations of leukotrienes and increased antioxidant and oxidase enzyme concentrations. The association between vitamin D status and a reduced inflammation has been noted in previous metabolomic studies that have identified vitamin D metabolites as potential biomarkers in inflammatory conditions, including asthma, 60 ankylosing spondylitis, 61 and obesity; 62 and is supported by studies highlighting the anti-inflammatory effects of vitamin D. [63][64][65][66] Vitamin D is known to play an extensive role in both innate and adaptive immunity, [67][68][69] but its role in the inflammatory process during pregnancy has not been established. A previous In a recent analysis of maternal vitamin D status and inflammation across adolescent pregnancy from the same cohort (n ¼ 168), Akoh et al found that maternal vitamin D status was correlated with tumor necrosis factor a (TNF-a) and C-reactive protein (CRP); analyses are ongoing to measure inflammatory cytokines (IL-6, IL-10, TNF-a, CRP) in archived maternal and cord serum (Unpublished results).…”

NK and NKT cell functions in immunosenescence

“…Moreover, the impaired NK cell cytotoxicity represents a high risk factor for the appearance of infections in advanced age. Studies in nonagenarian/centenarians showed an NK cell cytotoxicity that was similar in old subjects (aged 60-65 years) but higher than that in slightly older subjects (75 -85 years) (Sansoni et al ., 1992;Mariani et al ., 1999;Mocchegiani et al ., 2003). This suggests that preservation of NK cell cytotoxicity in middle age may be a crucial immune function in order to escape some age-related diseases and to reach healthy aging.…”

“…Findings in centenarian subjects and in very old mice confirm the relevance of zinc in restoring NK cell function in the elderly. Indeed, they have a well-preserved NK cell cytotoxicity, good zinc ion bioavailability and satisfactory IFN-γ production (Miyaji et al ., 2000;Mocchegiani et al ., 2003) as well as preserved thyroid hormone turnover (Mariani et al ., 1999). This last finding also supports, as described above, a sufficient maintenance of the neuroendocrine-immune network, via the zinc pool, in older individuals, contributing to avoidance of some age-related diseases.…”

Thyroid Hormones and the Heart; a Paradigm of Exquisite Fine Tuning, Combining Ancient Hellenic and Oriental Wisdom

“…TH may favorably influence innate immunity and natural killing activity [30][31][32][33]. This is a rapidly expanding field.…”