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A brief look at some 2020 research

By June 30, 2020 No Comments

 Mental Health

Several studies and reviews were recently published on the role of Obstructive Sleep Apnoea in depression and anxiety. As the rates of both of these mental health conditions continue to grow in general practice1, developing a multi-faceted approach to management of these conditions seems appropriate.

A review conducted out of Western Australia suggested a continued uncertainty in the suspected bidirectional relationship between depression and OSA2. It remains apparent however that there is significant overlap between the two conditions, and potential increase risk of developing depression if OSA is present2,3.

The review of the literature from Vanek et al. published in Sleep Medicine concluded there is a measurable decline in cognitive function in addition to an increase in depressive and anxious symptoms in patients with OSA. While verbal and psychomotor speed functions were less impacted, the literature suggested cognitive decline was somewhat irreversible after treatment with CPAP3.

Prevalence of depressive symptoms in OSA patients in an earlier review of the literature showed a pooled result of 35% and suggested preventative role of CPAP therapy as a valuable approach4.

Diabetic Nephropathy

A cross-sectional study from China published this year looked at the prevalence of diabetic nephropathy in hospitalised patients with Type II diabetes mellitus. Exclusion criteria was robust, and results showed several factors that were positively correlated to diabetic nephropathy including AHI. Arterial oxygen saturation nadir was also significantly associated with diabetic nephropathy, but interestingly mean saturation was not5, highlighting the importance of nocturnal oxygen nadirs in these patients.

The prevalence of OSA in hospitalised type II diabetic patients in this study was 88%, which was higher than the previously reported literature which suggested prevalence of OSA between 23 and 86%5.

A study published in Sleep Medicine highlighted the prevalence of chronic kidney disease in patients with OSA and obesity hypoventilation syndrome. Their study showed urine protein creatine ratio didn’t improve in these patients after CPAP therapy6, suggesting irreversible decline in kidney function in these patient groups.

Chronic Pain

Similar to the ambiguity surrounding sleep and mental health disorders, sleep and chronic non-cancer pain are consistently reported as being closely linked7,8,9,10, but with little consensus on whether sleep disturbance has direct causality to pain intensity and pain tolerance.

A study from Germany looked at improving both pain intensity and sleep quality using a motivational App that encouraged specific exercise, and found use of the App reduced pain intensity and sleep quality ratings7. The study however made no conclusions about if either were causal or dependent variables.

The study did support the hypothesis that exercise may be an intermediary factor between sleep quality and pain intensity. An American study published in BMJ showed the likelihood of pain development in middle-aged adults was significantly linked to physical exercise scores. Interestingly however, this association was lost in patients that reported some type of sleep disturbance8.

With both of these studies, sleep disturbance was self-rating, implicating subjective sleep quality as a possible correlate to pain. Indeed a large study published in SLEEP measured pain intensity and functional effect scores in conjunction with objective and subjective sleep metrics. Surprisingly, increased total sleep time and lower sleep fragmentation they found, was associated with higher pain intensity9. However poorer subjective sleep quality was associated with increased pain intensity, as was higher AHI9.

Including sleep disturbance management in chronic pain seems well warranted, however there is still much to learn between the two conditions.

 

References:

1. Hayes P. (2019) Mental Health issues increasing among Australians. RACGP. Retrieved online https://www1.racgp.org.au/newsgp/clinical/mental-health-issues-increasing-among-australians

2. Edwards C, Almeida OP & Ford, AH. (2020) Obstructive Sleep Apnea and Depression: A Systematic Review and Meta-Analysis. Maturitas. June 2020. In Press

3. Vanek J, Prasko J. et al. (2020) Obstructive sleep apnea, depression and cognitive impairment. Sleep Medicine. 72:50-58

4. Garbarino S, Bardwell WA. Et al. (2018) Association of Anxiety and Depression in Obstructive Sleep Apnea Patients: A Systematic Review and Meta-Analysis. Behavioural Sleep Medicine. 18(1).

5. Dong M, Guo F. et al. (2020) Association of diabetic nephropathy with the severity of obstructive sleep apnea-hypopnea syndrome in patients with type 2 diabetes mellitus. Endocrine Journal. 67(5):515-522

6. Sivam S, Yee BJ. Et al. (2020) Prevalence of Chronic Kidney Disease in Obesity Hypoventilation Syndrome and Obstructive Sleep Apnea with Severe Obesity. Sleep Medicine. May 2020. In Press

7. Priebe JA, Utpadel-Fischler D & Toelle, TR. (2020) Less Pain, Better Sleep? The Effect of a Multidisciplinary Back Pain App on Sleep Quality in Individuals Suffering from Back Pain – a Secondary Analysis of App User Data. Journal of Pain Research. 13:1121-1128

8. Whibley D, Guyer, HM. Et al. (2020) Sleep disturbance as a moderator of the association between physical activity and later pain onset among American adults aged 50 and over: evidence from the Health and Retirement Study. BMJ. 10(6)

9. Weingarten J, Dubrovsky B. et al. (2020) Retrospective Pain Reports In OSA Patients: Roles Of Depressive Symptoms, Polysomnographic And Self-report Sleep Measures. SLEEP. 43(Supp 1):A279

10. Amtmann D, Bamer AM. Et al. (2020) Cross-lagged longitudinal analysis of pain intensity and sleep disturbance. Disability and Health Journal. Feb 2020.