Nocturnal sentry duty and cardiometabolic characteristics in armed forces personnel

Abstract

Background: Sleep deprivation can lead to increased body weight and blood pressure (BP), but the latent effects of partial sleep deprivation related to required night sentry duties within a short-term period on cardiometabolic characteristic changes in military personnel are unclear.

Aim: To investigate the association between night sentry duty frequency in the past 3 months and cardiometabolic characteristics in armed forces personnel.

Methods: A total of 867 armed forces personnel who were aged 18-39 years and did not take any antihypertensive medications in Taiwan in 2020 were included. The frequency of night sentry duty was self-reported via a questionnaire (average number of night sentry shifts per month for the past 3 months). Hemodynamic status was assessed via the resting BP and pulse rate (PR). Cardiometabolic risk factors were defined according to the International Diabetes Federation criteria. Multivariable linear regression analyses of the associations between night sentry duties and PR, BP, and other metabolic syndrome (MetS) marker levels were performed, with adjustments for age, sex, substance use, body mass index and aerobic fitness. Multiple logistic regression analysis was carried out to determine the associations between night sentry duties and the prevalence of each MetS feature.

Results: There was an association between night sentry duties and PR [standardized β (standard error) = 0.505 (0.223), P =0.02], whereas there was no association with systolic and diastolic BP. In addition, there was an inverse association between night sentry duties and high-density lipoprotein cholesterol (HDL-C) levels [standardized β = -0.490 (0.213), P = 0.02], whereas there was no association with the other metabolic marker levels. Compared with personnel without night sentry duties, those with ≥ 1 night sentry shift/month had a greater risk of impaired fasting glucose (≥ 100 mg/dL) [odds ratio: 1.415 (confidence interval: 1.016-1.969)], whereas no associations with other MetS features were found.

Conclusion: Among military personnel, the burden of night sentry duty was positively associated with the resting PR but inversely associated with HDL-C levels. In addition, personnel with partial sleep deprivation may have a greater risk of impaired fasting glucose than those without partial sleep deprivation.

Keywords: Armed forces personnel; Cardio-metabolic characteristics; Night sentry duty; Partial sleep deprivation.