LAUSR

The relationship between sleep and micronutrients, including magnesium, is implicated in its regulation. The effects of low magnesium and other micronutrients on sleep disruption and telomere loss are not well understood. The present study was carried out in 172 healthy elderly subjects from South Australia. Plasma micronutrients including magnesium were measured. Each participant provided information about their sleep hours (<7 h or ≥7 h). Lymphocyte telomere length (TL) was measured by real-time qPCR assay. Plasma magnesium level was significantly low in subjects who sleep less than 7 h (p = 0.0002). TL was significantly shorter in people who are low in magnesium and sleep less than 7 h (p = 0.01). Plasma homocysteine (Hcy) is negatively associated with magnesium (r = −0.299; p < 0.0001). There is a significant interaction effect of magnesium and Hcy on sleep duration (p = 0.04) and TL (p = 0.003). Our results suggest that inadequate magnesium levels have an adverse impact on sleep and telomere attrition rate in cognitively normal elderly people, and this may be exacerbated by low levels of vitamin B12 and folate that elevate Hcy concentration.