Shift workers have higher body weight than day workers

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Monday, December 01, 2003 1:00 am Email this article
"Shift work [that is working on three regular rotating shifts] may be directly responsible for increased body fatness and is indirectly associated with higher blood pressure levels and some features of metabolic syndrome," concludes a recent study.`

OBESITY TWICE AS COMMON FOR SHIFT WORKERS

The prevalance of obesity was twice as common among shift workers as among day workers. Twenty percent of shift workers were obese compared to only 9.7 percent of day workers (p. 1355, col. 2).

FOOD EATEN ON NIGHT SHIFT WAS LOW FIBER, HIGH FAT, HIGH PROTEIN, HIGH GLYCEMIC INDEX

An interview performed by a dietician on a subgroup of these men doing shift work ?clearly showed that the common meal consumed during the night shift was poor in fibres and rich in animal proteins, saturated fat (cheese, ham, eggs, etc), and foods with high glycaemic index (white bread, sweets, etc), that is, a kind of food that is well known to predict an increase of body fat in working individuals? the researchers noted (p. 1357, col. 1).

GREATER BMI FOR THOSE DOING SHIFT WORK FOR 19-29 YEARS

Interestingly, the difference in the prevalance of obesity was only among men who had been doing shift work for 19 to 29 years.

There was no difference in BMI among men who had been doing shift work for 5 to 18 years compared to men who had been working days a similar amount of time (BMI of 27.6 versus 27.5). Nor was there any difference among men who had been doing shift work for more than 29 years compared to men working the day shift (BMI of 26.6 versus 26.6).

The place where the difference was seen was among those who had been doing shift work for 19 to 23 years (BMI of 27.7 versus 25.4), and among those who had been doing shift work for 24 to 29 years (BMI of 28.2 versus 26.7) (p. 1355, Table 2).

The average body mass index (BMI) was greater among shift workers than day workers, regardless of their age or work duration.

NO DIFFERENCE IN WAIST-TO-HIP RATIO

Even though shift workers weighed more than day workers, there was no difference in waist-to-hip ratio (0.97 versus 0.96) (p. 1355, Table 1).

HIGHER SYSTOLIC BLOOD PRESSURE

Shift workers also had significantly higher systolic blood pressure which seemed to be the result of a higher BMI (131 mmHg versus 126 mmHg) (p. 1355, Table 1).

SHIFT WORKERS HAVE AN INCREASED RISK OF HEART DISEASE

A number of previous studies have reported an increased risk of coronary heart disease in shift workers and an association between the relative risk and the amount of time that a person has been exposed to shift work.

Other studies have also reported larger weight gain in people who do shift work.

The time of day that these shift workers worked every eight days were two days they worked nights, two days they worked afternoons, two days they worked mornings, then they had three days off.

OBESE HAVE MORE ACCIDENTS AND INJURIES AT WORK

Interestingly, they also note that studies have found that obesity is associated with an increased risk of accidents and injuries at work.

ROTATING SHIFTS INCREASE CORTISOL

Rotating shifts causes a rise in the stress hormone cortisol. Normally cortisol rises in the morning and falls at night, however in people on rotating shifts there is a loss of this rhythm, leading to a progressive rise in cortisol levels during sleep.

They noted that higher cortisol levels can cause insulin resistance in muscles (p. 1357, col. 2).

The current study looked at 319 men, aged 35- to 60-years-old who were blue colar workers in Southern Italy,.

REFERENCE

Di LL, De PG, Zocchetti C, L’abbate N, Basso A, Pannacciulli N, Cignarelli M, Giorgino R, Soleo L. Effect of shift work on body mass index: results of a study performed in 319 glucose-tolerant men working in a southern italian industry. Int J Obes Relat Metab Disord. 2003 Nov, 27(11):1353-58.

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• Night workers/shift workers