In the Journals

Diabetes, metabolic disorders linked to urban stressors

Show Citation

December 18, 2014

Diabetes and metabolic disorders may be more common among people in developing nations who live in cities vs. those who remain in rural areas because of increased stress affecting hormone levels, according to recent study findings.

“Our findings indicate that people who leave a rural lifestyle for an urban environment are exposed to high levels of stress and tend to have higher levels of the hormone cortisol,” Peter Herbert Kann, MD, PhD, MA, of the Philipp University of Marburg, Germany, said in a press release. “This stress is likely contributing to the rising rates of diabetes we see in developing nations.”

Kann and colleagues evaluated men and women aged 30 to 80 years of the Ovahimba people from Namibia in southwestern Africa to determine the prevalence of disorders and glucose metabolism. Participants were divided into two groups: urban, living in the regional capital of Opuwo (n=60); and rural, living at least 50 km away from the nearest village or town (n=63).

The urban group had a higher prevalence of glucose metabolism disorders (28.3%) vs. the rural group (12.7%; P=.04). Significantly higher cortisol levels also were found among the urban group compared with the rural group.

Compared with the rural group, the urban group had greater changes in hip circumference (P<.001), waist circumference (P<.001), BMI (P=.014), systolic blood pressure at rest (P<.001), diastolic BP at rest (P=.002), systolic BP after exercise (P<.001), heart rate after exercise (P=.007), fasting glucose (P<.001), 2-hour glucose by oral glucose tolerance test (P=.002), triglycerides (P=.04), HDL cholesterol (P=.014) and prevalence of metabolic syndrome (P<.001). The rural group exhibited higher LDL cholesterol levels compared with the urban group.

The rural group participated in more intense physical activity, whereas the urban group ate more fast food.

“The results suggest sociocultural instability caused by urbanization contributes to an increased risk of developing diabetes or another metabolic disorder,” Kann said in the release. “This is the first prospective study to systematically show the body’s regulation of the hormone cortisol plays a part in the metabolic changes brought on by the shift to an urban lifestyle.”

Disclosure: The study was funded in part by Novo Nordisk.

itj+ Infographic

itj+ Perspective