Effect of Altered Sleep Rhythm on Body Mass Index

Abstract

Objective: To assess the influence of de-synchronized sleep rhythm caused by rotatory shift work on Body Mass Index (BMI) in health care providers. Methodology: This cross-sectional study was conducted in Dow university hospital Karachi, from November 2013 to May 2015. To outline underlying risk factor for obesity, a universal sample of all eligible health care providers working in split shifts (service across 24 hours of the clock, each day of the week)(n=91) were enlisted. We used the BMI calculator of heart foundation Australia. However, Asian cutoff points by WHO were also taken into consideration (BMI classification Global data base on BMI, WHO 2006) whereby BMI above 25 was considered to be obese in the Asian countries (WPRO criteria). BMI was determined by using metric system. Height was recorded in centimeters and weight was obtained in kilograms. Gender based BMI was calculated for adult men and women. The healthy range of BMI was 18.5-25. Exclusion criteria included pregnant women, age less than 18 years and chronic illness. Results: Results revealed an increased BMI amongst the shift workers. However, female health care providers far outnumber the male health care providers as it was observed that 16 women (43.2%) were found to have BMI more than 25 as compared to 9 (16.7%) men. Conclusion: Split shift work was identified as independent risk factor for obesity. Identification of irregular sleep cycle as an underlying mechanism leading to obesity necessitates further evaluation