Dados do Trabalho

Título

Association of Social Jet Lag with Body Mass Index Among Brazilian Adults

Introdução

Obesity is a serious public health problem worldwide, it is estimated that by 2035, 50% of the world's population will be overweight. In recent years, new risk factors for obesity have been identified, including insufficient sleep and circadian misalignment.

Objetivo

Evaluate whether social jet lag, a proxy of circadian misalignment, is associated with BMI and overweight.

Métodos

This study utilized data from the SONAR-Brazil Survey (n=2,050, aged 18-65 years, data collection: 2021-2022). Body Mass Index (BMI) (kg/m²) was calculated using self-reported height (m) and weight (kg). Overweight was defined as BMI ≥25.0 kg/m². Social jet lag (SJL) was determined by the absolute difference between the midpoint of sleep on weekends and weekdays and was analyzed both as continuous variable (in hours) and categorical (>1h, 1-2h, and >2h). The association between SJL and BMI (outcome) was verified using the multiple linear regression, adjusted for sex, age, chronotype, education level, physical exercise, diet quality, and weekly average sleep duration.

Resultados

The average BMI among participants was 25.14kg/m², with a 44% prevalence of overweight. The variability in weekend sleep duration was 42min, and the midpoint of sleep exhibited a variability of 21min. The prevalence of SJL was 12.54%. In the comparison between groups with SJL and non-SJL, those with SJL had a higher BMI (25.8kg/m² versus 25.04kg/m², p: 0.02). Each additional hour of SJL was associated with a BMI increase of 0.71kg/m² (95%CI: 0.22; 1.19, p:0.004). For participants with SJL >2h, BMI increased by 2.29kg/m² (95% CI: 0.84; 3.74, p:0.002). The magnitude of these effects to be correlated with level of SJL, that BMI increases as SJL increases (<1h: 25.0 kg/m², 1-2h: 25.6 kg/m², >2h: 25.8kg/m²).

Conclusões

Our findings, showing that social jet lag correlates with higher BMI values, indicate the need to include strategies for improving sleep consistency and regularity in clinical protocols and public health guidelines aimed at preventing ant treating overweight and obesity.

Funding: This work was supported by ‘Fundação de Amparo à Pesquisa do Estado de Alagoas - FAPEAL’ (Grant/Award Number: 60030.0000002539/2022).

Palavras -chave

Sleep. Chronobiology. Social Jet lag. Body Mass Index. Overweight.