Later chronotype is associated with higher hemoglobin A1c in prediabetes patients

Abstract

The circadian system is known to play a role in glucose metabolism. Chronotype reflects the interindividual variability in the phase of entrainment. Those with later chronotype typically prefer later times in the day for different activities such as sleep or meals. Later chronotype has been shown to be associated with metabolic syndrome, increased diabetes risk and poorer glycemic control in type 2 diabetes patients. In addition, "social jetlag", a form of circadian misalignment due to a mismatch between social rhythms and the circadian clock, has been shown to be associated with insulin resistance. Other sleep disturbances (insufficient sleep, poor sleep quality and sleep apnea) have also been shown to affect glucose metabolism. In this study, we explored whether there was a relationship between chronotype, social jetlag and hemoglobin A1c (HbA1c) levels in prediabetes patients, independent of other sleep disturbances. A cross-sectional study was conducted at the Department of Family Medicine, Ramathibodi Hospital, Bangkok, from October 2014 to March 2016 in 1014 non-shift working adults with prediabetes. Mid-sleep time on free day adjusted for sleep debt (MSFsc) was used as an indicator of chronotype. Social jetlag was calculated based on the absolute difference between mid-sleep time on weekdays and weekends. The most recent HbA1c values and lipid levels were retrieved from clinical laboratory databases. Univariate analyses revealed that later MSFsc (p = 0.028) but not social jetlag (p = 0.48) was significantly associated with higher HbA1c levels. Multivariate linear regression analysis was applied to determine whether an independent association between MSFsc and HbA1c level existed. After adjusting for age, sex, alcohol use, body mass index (BMI), social jetlag, sleep duration, sleep quality and sleep apnea risk, later MSFsc was significantly associated with higher HbA1c level (B = 0.019, 95% CI: 0.00001, 0.038, p = 0.049). The effect size of one hour later MSFsc on HbA1c (standardized coefficient = 0.065) was approximately 74% of that of the effect of one unit (kg/m 2 ) increase in BMI (standardized coefficient = 0.087). In summary, later chronotype is associated with higher HbA1c levels in patients with prediabetes, independent of social jetlag and other sleep disturbances. Further research regarding the potential role of chronotype in diabetes prevention should be explored. ARTICLE HISTORY

Social jetlag and metabolic control in non-communicable chronic diseases: a study addressing different obesity statuses

“…In our study, social jetlag was not related to HbA1c levels (Table 2), as also found in other studies 17, 18 . According to Anothaisintawee et al .…”

“…16 , found in patients with type 1 diabetes a positive association between HbA1c and social jetlag (β = 0.012, p < 0.001); HbA1c levels were lower in patients with social jetlag below (≤49 min) versus above (>49 min) the median (7.7% and 8.7%, respectively; p = 0.011). However, in two studies also examining the associations between social jetlag and glycaemic control markers, conducted in pre-diabetic subjects 18 and type 2 diabetes patients 17 , no significant associations were found between circadian misalignment and metabolic control. Two other studies involving the general population 12, 15 revealed that social jetlag is related to a worse metabolic pattern, such as higher fasting plasma insulin, insulin resistance and higher LDL-c and triglyceride levels (p  <  0.05) 12, 15 .…”

“…In a few studies that have analysed patients with metabolic abnormalities, social jetlag has been significantly associated with HbA1c levels in type 1 diabetes individuals (n = 80; 46% female) 16 . However, no associations have been found between social jetlag and parameters related to glycaemic control in type 2 diabetics 17 or pre-diabetic individuals 18 . Thus, this is a topic still little explored that demonstrates the need to carry out new studies.…”

Clocks in the clinic: circadian rhythms in health and disease

“…In addition to this, a recent study from the UK BioBank comparing definite evening and definite morning types identified an increased likelihood of diabetes in evening orientated individuals with an OR of 1.30 8. Later chronotype is associated with higher HbA1c levels, independent of confounding sleep and clinical variables, in T2DM83 and prediabetes 84. There are conflicting reports of the association of chronotype with glycaemic control in type 1 diabetes: one study reports that more SJL is associated with poorer glycaemic control in adults,85 while in an adolescent cohort chronotype or SJL was not associated with HbA1c levels 86…”

Nutritional support and dietary interventions for women with polycystic ovary syndrome

“…135 People with prediabetes preferring to consume their main meal in the evening (later chronotype) had higher HbA1c compared to those consuming their main course at lunch time, and thus, had higher risk of developing type 2 diabetes sooner. 136 The American Heart Association in their recent scientific statement concluded that meal frequency and timing may be important parameters in the nutrition management of chronic diseases, leading to healthier lifestyle and reduction in cardiometabolic risk factors. 128 …”