Elderly sleep apnoea sufferers may live longer

New research results suggest that sleep apnoea which has often been linked to increased rates of cardiovascular morbidity and mortality may actually contribute to higher survival rates in the elderly. The findings by Technion-Israel Institute of Technology researchers were presented last Thursday at the bi-annual European Sleep Research Society Congress in Glasgow, Scotland.

Led by Prof Peretz Lavie of the Faculty of Medicine, the study was conducted over a 4.5-year period, with researchers comparing mortality rates among elderly subjects diagnosed with sleep apnoea to those of the elderly in the general population. Results were divided by to age, sex, and ethnic origin.

When mortality rates of 611 elderly patients with "light or no" sleep apnoea, "moderate" sleep apnoea, and "severe" sleep apnoea were compared with the general population, those suffering from moderate sleep apnoea had a mortality rate one-third of that of the general population. And mortality rates for the elderly with no sleep apnoea, light sleep apnoea and severe sleep apnoea were on par with those of the general populace.

"These findings, when combined with new findings in scientific literature of the adaptive influences of intermittent hypoxia (lack of oxygen) in various clinical models, strengthens our hypothesis that sleep apnoea activates defence mechanisms among the elderly that provide them with survival advantage," said Lavie.

Although sleep apnoea is more prevalent among the elderly than among the young and middle-aged, the medical implications among the elderly are still not well known.

Affecting 10 percent of men and five percent of women, sleep apnoea has been found to constitute a significant risk for cardiovascular morbidity and mortality. The findings from many studies including some conducted at the Technion show patients with sleep apnoea are at a higher risk for mortality, particularly if they are overweight.

The research was conducted in the Lloyd Rigler Laboratory for Sleep Apnoea Research at the Technion Faculty of Medicine.

(Source: European Sleep Research Society Congress: Technion-Israel Institute of Technology: September 2008)