Document Type : Original Article
Authors
1 Department of Occupational Health Engineering, Faculty of Medicine, University of Tarbiat Modares
2 Department of Occupational Health Engineering, School of Health, Shahid Beheshti University of Medical Sciences, Tehran, I. R. Iran
3 Environment Research Center, School of Health, Isfahan University of Medical Sciences, Isfahan
Abstract
Background: In the hot weather, overweight and obesity are considered as significant risk
factors for the incidence of cardiac strain in workers. This study is aimed at comparing the
cardiac strain among overweight and normal‑weighted workers, in the hot, humid conditions
of the south of Iran. Materials and Methods: This cross‑sectional study was conducted
on 71 workers in the south of Iran, in the summer of 2010.The heart rate was measured at
rest and at actual work. Cardiac strain based on the working heart rate (WHR), the relative
cardiac cost (RCC), the net cardiac cost (NCC), the load relative cardiovascular (CVL), and
heart rate reduction were analyzed in 35 normal weight people (BMI <25) and 36 people who
were overweight (BMI >25), using descriptive statistics and t‑ tests. Results: In 42% of the
total workers, the body mass index was more than 25. The average temperature of the two
groups was not significantly different. The mean WHR in these two groups was 101 ± 20.3
and 112 ± 18.9, respectively (P = 0.026). Percentages that exceeded the acceptable limits
in parameters of NCC, RCC, WHR, CVL, and the Brouha index, were significantly higher in
overweight people than those in people with normal weight. Conclusions: Based on the study
results, the severity of cardiac strain was higher in overweight workers when compared with
normal weight workers. Hence, in order to decrease the cardiac strain, selecting overweight
individuals for these jobs should be avoided, as also some vital intervention for losing weight,
such as, nutrition education and encouraging them to increase their physical activity, should
be implemented.
Keywords
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