OSA is independently associated with an increase in the cardiovascular risk factors that comprise the metabolic syndrome and its overall prevalence. This may help explain the increased cardiovascular morbidity and mortality associated with this condition.

Obstructive sleep apnoea is associated with increased blood pressure and other features of the metabolic syndrome. The aim of the present study was to determine the relative effectiveness of continuous positive airway pressure (CPAP) in modifying these outcomes.A randomised placebo-controlled blinded crossover trial comparing cardiovascular and metabolic outcomes after 6 weeks of therapeutic and sham CPAP was performed in 34 CPAPnaïve patients (mean¡SD body mass and respiratory disturbance indices were 36.1¡7.6 and 39.7¡13.8, respectively).Mean waking systolic and diastolic blood pressure fell by 6.7 and 4.9 mmHg, respectively, when compared with sham CPAP. No change was observed in glucose, lipids, insulin resistance or the proportion of patients with metabolic syndrome. In CPAP-compliant patients the fall in blood pressure was greater and the baroreceptor sensitivity improved significantly but no metabolic variable changed.In obese Caucasians with untreated obstructive sleep apnoea, continuous positive airways pressure can improve baroreceptor responsiveness and reduce waking blood pressure within 6 weeks, but this treatment period was insufficient to modify insulin resistance or change the metabolic profile. The mechanisms underlying this difference in the time course of blood pressure and metabolic response to continuous positive airway pressure in obstructive sleep apnoea requires further exploration.

Transient insulin-induced hypoglycaemia increases energy intake. Participants consumed more fat after insulin compared to that after saline. High-fat foods can lead to passive overconsumption and have a low glycaemic index, which may prolong hypoglycaemia. Both factors could ultimately promote weight gain in individuals with recurrent hypoglycaemia.

Melatonin and bright-light phototherapy appear ineffective in CFS. Both treatments are being prescribed for CFS sufferers by medical and alternative practitioners. Their unregulated use should be prohibited unless, or until, clear benefits are convincingly demonstrated.

Fourteen ambulatory subjects, varying in their amount of habitual physical activity, were studied for 24 h during a total of 25 "typical" days. Rectal temperature was recorded every 6 minutes, an activity diary was filled in every half hour, and wrist activity and heart rate were monitored every minute. Actimetry and heart rate data generally showed close parallelism with each other and with the masking effects on body temperature. Psychological stressors such as public speaking produced a greater effect on heart rate and body temperature than on wrist movement, while typing produced high values for wrist movement, but affected heart rate and temperature much less. When data for the circadian rhythm of body temperature were purified, the diary, actimetry, and measurement of heart rate were all useful in reducing masking effects, but the present evidence indicates that heart rate can be more successful than actimetry--as judged by the closeness of the purified data to a sinusoid. This superiority of heart rate monitoring over wrist activity as a method of purification might be because core temperature can be increased by stressor-induced thermogenesis, as well as by physical activity, and because wrist movement can, with some activities, give an inaccurate estimate of the factors that contribute to whole-body thermogenesis.