A1c, Sleep Quality and Duration in Prediabetes Patients

There is growing evidence suggesting that the quality and duration of sleep may contribute to the risk of prediabetes progressing to type 2 diabetes.

Four hundred fifteen million people globally are affected by type 2 diabetes. Impaired fasting glucose and glucose tolerance are called prediabetes. Prediabetes describes an increased risk of developing type 2 diabetes. Lifestyle changes, such as diet and physical activity, can reduce the incidence of type 2 diabetes by more than 50% for those with prediabetes. Sleep curtailment is a behavior that has become highly prevalent over the past few decades. About one-third of the adult population sleeps less than 6 hours per night. Sleep loss over time is a significant risk factor for increased weight and insulin resistance, increasing the risk of developing type 2 diabetes. There has been a significant association between sleep deprivation and type two diabetes in women. Growing evidence suggests that sleep duration and sleep quality contribute to the type 2 diabetes epidemic. 

This study took place between January 2019 and April 2019, with participants on a National Health Service England-funded Healthier You: National Diabetes Prevention Program. This study was a retrospective observational cohort study to assess the relationship between the elevation of HbA1c level, sleep quality, and sleep duration in clinically diagnosed individuals with prediabetes. Each participant received a pre-program information pack with sleep quality and sleep duration questionnaire at the end of their initial appointments. The Pittsburgh Sleep Quality Index was used to assess sleep quality and duration. This scale evaluated sleep quality and sleep duration over one month. It is a 19 item self-rated questionnaire that generates seven sleep component scores on a scale of 0-3, 3 indicating the most significant dysfunction. Poor sleep quality was defined as a score greater than five on the Pittsburgh Sleep Quality Index. Sleep duration was defined as the number of hours individuals spent sleeping. 

For the relationship between HbA1c and sleep quality, the cohort reported a significant large positive association (rs= 0.913, p<0.001) between HbA1c (mmol/mol) and sleep quality. The relationship between HbA1c and sleep duration showed a large negative association (rs=-0.757, p < 0.001) between HbA1c elevation level and sleep duration. The main findings from this study were that the participants with a higher HbA1c elevation level had a higher global PSQI score/decreased sleep quality. It was also shown that an increase in sleep duration resulted in a decreased HbA1c level. Brain glucose utilization was shown to be considerably reduced during total sleep deprivation. Sleep restriction over time was shown to cause morning insulin resistance. The secondary outcomes were to break down the male and female HbA1c. The relationship between female HbA1c and sleep quality reported a large positive association (rs= -0.868, p < 0.001). The relationship between female HbA1c and sleep duration reported a large negative association (rs = -0.723, p < 0.001). The relationship between male HbA1c and sleep quality reported a significant positive association (rs= -0.972, p < 0.001). The relationship between male HbA1c and sleep duration reported no significant association (rs= 0.218, P = 0.454). These results show that females with a higher HbA1c elevation level have a higher global PSQI score/decreased sleep quality. Results also concluded that for female patients, increased sleep duration resulted in a decreased HbA1c. Males with a higher HbA1c elevation level had a higher global PSQI score/decreased sleep quality; however, no association between HbA1c level and sleep duration was reported for male participants. 

This study found a significant relationship between the elevation of HbA1c level, sleep quality, and sleep duration. Further research should be conducted using more accurate sleep quality and sleep duration measurements to ensure more accurate sleep restriction and sleep fragmentation results. The PSQI questionnaire is a personal tool used to measure sleep. Self-reporting used as a tool for this study is subjective and can reflect inaccurate information. Further studies on the relationship of sleep quality and sleep duration to other diabetes risk factors like body mass index and waist circumference could be beneficial in treating diabetes patients.   

Practice Pearls: 

• Participants from the National Health Service England-funded Healthier You: National Diabetes Prevention Program received a sleep quality and sleep duration questionnaire at baseline. 
• Elevated HbA1c in female patients correlated with poor sleep quality and sleep duration. Elevated HbA1c levels in males correlated with poor sleep quality, but there was no significant correlation with sleep duration. 
• Further studies with more accurate measurements of sleep duration should be conducted. 

Reference for “A1c, Sleep Quality and Duration in Prediabetes Patients”:
Kass L, Sanderson JC, Desai T, Hurst R. The relationship between the elevation of hemoglobin A1c level, sleep quality and sleep duration in clinically diagnosed prediabetic patients in a nationally representative sample. Diabetes and Vascular Disease Research. January 2022. doi:10.1177/14791641211067421 

Emily Walser, PharmD Candidate 2022, Lake Erie College of Osteopathic Medicine, College of Pharmacy