Habitual sleep deprivation is associated with type 2 diabetes: a case-control study

Objectives: It is suggested that a minimum of eight hours of sleep per night is needed for metabolism to work normally. The aim of the study was to determine the association of habitual sleep deprivation and type 2 diabetes mellitus [T2DM]

Methods: We conducted a case-control study comparing patients with T2DM with age and sex matched healthy controls. Standard sleep questionnaires [the Berlin and Epworth Sleepiness Scale] and a weekly diary were used by patients to self-report habitual sleep

Results: A total of 172 diabetics and 188 healthy controls were enrolled in the study. There was a significant difference between T2DM and healthy controls in nocturnal sleep duration [p = 0.033]. There was a significant association between nocturnal sleep duration of fewer than six hours and T2DM [X[2] = 14.0; p = 0.0001]. There was no significant difference in daytime sleepiness and daytime naps between the T2DM and control groups [p = 0.452; p = 0.581, respectively]

Conclusions: A nocturnal sleep duration < 6 hours is associated with T2DM

Reference values for arterial stiffness indices in an Omani Arab population

To determine the reference values of arterial stiffness indices, particularly augmentation index [AIx] and pulse wave velocity [PWV] using applanation tonometry in a healthy Omani Arab population. This prospective study was carried out in the Department of Clinical Physiology, Sultan Qaboos University Hospital, Muscat, Oman over a 2-year period from June 2011 to June 2013. The central AIx, aortic PWV [AoPWV], and central pulse pressure [CPP] were recorded from 120 healthy subjects recruited randomly from a normal population using a SphygmoCor device. The 2.5[th] and 97.5[th] percentiles were used to determine the reference ranges for men and women separately. Analyses were performed using univariate statistics. The mean age of the cohort was 38 years for men, and 35 years for women, with the ages ranging from 20-53 years. The overall mean central AIx was 13 +/- 11%, and for AoPWV was 6.7 +/- 1.6 m/s. The central AIx was higher in women [17 versus 10%; p<0.001], whereas the AoPWV was higher in men [7.1 versus 6.3 m/s; p=0.003]. Subjects were categorized according to the gender and age decade, and reference values for CPP, central AIx, and AoPWV were obtained. This study reports the reference values for arterial stiffness indices from an Omani Arab population; the results of which should be interpreted in the context of its limitations

Snoring-induced nerve lesions in the upper airway

The prevalence of habitual snoring is extremely high in the general population, and is reported to be roughly 40% in men and 20% in women. The low-frequency vibrations of snoring may cause physical trauma and, more specifically, peripheral nerve injuries, just as jobs which require workers to use vibrating tools over the course of many years result in local nerve lesions in the hands. Histopathological analysis of upper airway [UA] muscles have shown strong evidence of a varying severity of neurological lesions in groups of snoring patients. Neurophysiological assessment shows evidence of active and chronic denervation and re-innervation in the palatopharyngeal muscles of obstructive sleep apnoea [OSA] patients. Neurogenic lesions of UA muscles induced by vibration trauma impair the reflex dilation abilities of the UA, leading to an increase in the possibility of UA collapse. The neurological factors which are partly responsible for the progressive nature of OSAS warrant the necessity of early assessment in habitual snorers

audit of the sleep medicine service in Oman

To audit the sleep service at Sultan Qaboos University Hospital [SQUH], Muscat, Oman, and to explore deficiencies to introduce new measures of improvement. Polysomnography [PSG] reports and SQUH medical records of all patients who underwent sleep studies from January 1995 to December 2006 in the sleep laboratory at SQUH were reviewed and analyzed. Out of a total of 1042 sleep studies conducted in the specified period, 768 PSG recordings were valid for analysis. The audit showed that the Otolaryngology Department was the main referring specialty for PSG [43%]. Snoring was the main symptom for 33% of the subjects referred, but suspicion of obstructive sleep apnea was the main reason for referral [38%]. Three quarters of the patients were males who were also younger, and with lower body mass index compared to females [p=0.0001 for all]. Despite large number of patients with an apnea-hypopnea index of >15 [n=261], only 94 [36%] patients received continuous positive airway pressure titrations and treatment. The sleep medicine service in SQUH provided the basic service, and raised the awareness of the importance of this specialty. However, substantial effort is required to bring it to international standards

Obstructive sleep apnoea/hypopnoea syndrome and hypertension

The obstructive sleep apnoea/hypopnoea syndrome [OSAHS] is a common disorder, affecting around 2-4% of the middle-aged population. There is a strong association between OSAHS and hypertension, based on animal, large epidemiological and interventional studies. The epidemiological studies have shown a dose-response relationship between apnoea/hypopnoea index [AHI] and the risk of developing hypertension. Different mechanisms may have a role in the process of elevated blood pressure in OSAHS. Sympathetic activity is increased in OSAHS patients during sleep and wakefulness. This increase in sympathetic activity is probably due to activation of baroreflexes and chemoreflexes by frequent arousals and hypoxaemia a result of apnoea or hypopnoea events. Continuous positive airway pressure [CPAP] has been shown to reduce sympathetic stimulation and blood pressure in OSAHS patients. Altered endothelial function may also have a role in the pathogenesis of hypertension in OSAHS subjects. Reduction of nitric oxide [NO] production and increase in the formation of free radicals may be responsible for the impairment of the vasodilatation of micro-vasculature in these subjects as a result of hypoxaemia. It has been shown that effective CPAP therapy has a reversible effect on endothelial dysfunction