Does sleep deprivation make sleep apnea worse?

Over the past two decades, the prevalence of sleep apnea has become increasingly apparent. Chronic sleep deprivation resulting in daytime sleepiness is a well recognized consequence of sleep apnea. But does chronic sleep deprivation cause sleep apnea?

An article published in a recent issue of the journal Sleep (August, 2017) investigated this. Rats were assigned to three groups: one experienced chronic sleep restriction for 21 days by housing in a cage designed to limit sleep time. Previous studies have shown that the cage design results in near complete REM sleep deprivation and a 35% to 40% reduction in non-REM sleep (NREM). There were two control groups: one control group was housed in a cage designed to appear similar to the treatment cage but not notably restricting sleep, another control group was housed in a standard vivarium cage. After the 21 day period, the size of four respiratory areas (nuclei) in the brainstem were analyzed for size and number of neurons. Both the number of neurons and the size of the nuclei of the chronically sleep restricted animals were reduced as compared to either of the control groups.

Since the brainstem nuclei are part of normal breathing control, this study suggests that chronic sleep restriction may have deleterious effects on respiration. Further extrapolation is tenuous but it is not unreasonable to suspect that such chronic sleep restriction may contribute to the progression of sleep apnea since sleep apnea is known to result in sleep restriction.

Practical Health Strategies (www.practicalhealthstrategies.com), offers wellness programs in the Pensacola, Panama City and Mobile area, and throughout north Florida, and south Alabama, Georgia, and Mississippi. Wellness Plans you can Live With!

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Does shiftwork shorten your life?

Shiftwork and regular jet-lag is deleterious to your health and has been associated with increased adiposity (fat) and obesity, insulin resistance and type 2 diabetes, and cardiovascular disease. We tend to see these same changes as we age and it has been suggested that shiftwork ages us more rapidly. In the general press, this is often attributed to sleep loss, however, another likely mechanism could be the disruption of the biological clock and daily (“circadian”) rhythm.

A recent study published in the journal of the Federation of American Societies of Experimental Biology (FASEB Journal, April, 2017) subjected rats to simulated shiftwork for three months. A group of young Sudanian grass rats (which sleep during the nighttime like most people instead of the daytime like most rats) were subjected to a 10 hour shift in their light/dark cycle during four days each week while returning to a normal cycle on the weekends. This would be similar to someone working four nights per week but returning to a daytime lifestyle for the remaining three days per week. We will call this group the “shiftwork” or “SW” group. The control group of young rats stayed on a regular light/dark routine throughout the study. There was a second, smaller comparison group of old rats that had been maintained on a regular light/dark.

The magnitude of the change (10 hrs) and the frequency (every 3 or 4 days) prevented the biological, circadian rhythm from following the shift as shown by recordings of daily activity/rest periods. This indicates desynchronization of the biological rhythms. The researchers recorded a number of indicators related to metabolic aging including glucose tolerance, fat pad thickness, and DNA damage but, of particular interest was telomere length and SIRT1. The telomere is a protective end on chromosomes which progressively shortens with age. SIRT1 is a protein believed to be important in regulating gene expression and decreases with age. Telomere length and SIRT1 levels are generally recognized as cellular indicators of aging and are the interest of this Health Update.

The results: A fourth of the SW animals were able to shift their daily rhythm each time while three-fourths were not and became desynchronized. This is consistent with studies on people working shiftwork.

The young control animals had the longest telomeres and the old comparison rats had the shortest telomeres. The young SW animals had intermediate telomere lengths. This indicates cellular aging was accelerated. The SIRT1 levels were lowest in the old comparison group, intermediate in the SW animals, and highest in the young control rats. Similar to the telomere data, this implies cellular aging was accelerated.

Shiftwork is a fact of life in many industries and businesses. This study and others suggest, however, a significant cost to society at large and to the individuals. Both employers and individuals should consider ways to ameliorate the damage.

Practical Health Strategies (www.practicalhealthstrategies.com), offers wellness programs in the Pensacola, Panama City and Mobile area, and throughout north Florida, and south Alabama, Georgia, and Mississippi. Wellness Plans you can Live With!

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Moderate Exercise Amount is (almost) as Good as a High Exercise Amount

The beneficial health effects of physical activity and exercise are well established but the optimal amount and intensity of exercise continues to be debated. Many studies have suggested that, while increasing exercise levels provide increasing health benefits, the most benefit comes from the first increase in exercise.

An article in the May, 2014, issue of the journal Obesity investigated the “dose-response” of exercise on health risks. The subjects were healthy young (ages 20 to 40), sedentary and overweight men. The participants were screened for health status based on medical history, blood pressure, fasting blood glucose levels, stable weight, and no regular medications. After the screening, sixty-four subjects were randomized into three groups: no change in activity levels (control group), moderate (MOD) increase in activity levels (daily exercise expending 300 Calories), and high (HIGH) increase in activity levels (daily exercise expending 600 Calories). Fifty-three subjects completed the study balanced among the groups.

Subjects adhered to individual exercise prescriptions to attain the specified energy expenditure and intensity and the prescriptions were adjusted at intervals. The prescriptions called for three days per week of high intensity sessions with the other days calling for lower intensity but longer time to maintain the required energy expenditure. Compliance was good with average recorded energy expenditures of 337 and 644 Calories per exercise session in the MOD and HIGH groups, respectively, and average weekly expenditures of 2004 and 3774 Calories, respectively. Subjects were encouraged to vary the exercise mode to avoid injuries. Measures included anthropometrics (weight, height, body composition, waist and hip circumferences), blood pressure, glucose tolerance and insulin sensitivity, a quality of life survey, cardio-respiratory fitness (CRF) determined by oxygen uptake during a graded exercise test, muscle biopsies to determine muscle energy capacity, and blood lipid parameters and an inflammatory marker (CRP).

Both exercise groups lost significant weight, exclusively due to loss of fat mass, with the MOD group actually losing more weight than the HIGH group and both groups lost waist circumference. CRF improved in the exercise groups to a similar degree. Insulin sensitivity improved in both exercise groups, more so in the HIGH group. Muscle energy capacity increased in both exercise groups similarly. Both groups showed a similar improvement on the quality of life survey.

The authors concluded there was “only minor additional effect” of the higher amount of exercise on health parameters over the time period of the study in the young, healthy, moderately overweight subjects. This supports other studies suggesting that any exercise brings benefit.

Practical Health Strategies (www.practicalhealthstrategies.com), offers wellness programs in the Pensacola, Panama City, Fort Walton and Mobile areas, and throughout north Florida, and south Alabama, Georgia, and Mississippi. Wellness Plans you can Live With!

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