Telomere Length in Sleep Apnea!!!

Good health and happiness are impossible when we are robbed of sleep for very long. For many people, this is all too often a way of life. Sleep apnea is a sleep disorder characterized by pauses in breathing during sleep. Each episode, called an apnea, lasts long enough so that one or more breaths are missed, and such episodes occur repeatedly throughout sleep. Clinically significant levels of sleep apnea are defined as five or more episodes per hour of any type of apnea. There are three distinct forms of sleep apnea: central, obstructive, and complex.

A telomere is a region of repetitive DNA at the end of a chromosome, which protects the end of the chromosome from deterioration. Telomeres are extensions of the linear, double-stranded DNA molecules of which chromosomes are composed, and are found at each end of both of the chromosomal strands. Thus, one chromosome will have four telomeric tips. In humans, the forty-six chromosomes are tipped with ninety-two telomeric ends. Shorter (systemic) telomere length has been suggested as an independent risk factor for cardiovascular disease. The origin of this association is unclear and several models have been proposed, particularly attributing the biomarker value to a genetic predisposition in subjects with shorter telomeres, to an effect of inflammation and oxidative stress or to a combination of both.

Researchers have found that in several chronic health conditions such as diabetes and atherosclerosis there has been a shortening of the telomere length and this could be due to oxidative stress and inflammation. These conditions also occur in patients with obstructive sleep apnea syndrome so a team of researchers decided to investigate whether there was a reduction in telomere length in patients with sleep apnea and if telomere length was associated with the severity of sleep apnea, the presence of metabolic disorders and/or risk factors for cardiovascular disease. They recruited 256 patients with obstructive sleep apnea syndrome and 148 controls without sleep apnea. The results were a significant reduction of telomere length in patients with sleep apnea in comparison to the control group. There was not an association between telomere length and chronological age, severity of sleep apnea, metabolic disorders and/or presence of cardiovascular alterations. The authors concluded that there is potential in using telomere length as a biomarker for increased risk of cardiovascular disease in patients with sleep apnea and justifies further studies.1

1 Barcelo A, Peirola J, Lopez-Escribano H, et al. Telomere shortening in sleep apnea syndrome. Respir Med. Apr2010.