BOSTON — Elderly men living in homes with a higher daytime temperature in the winter also had greater abdominal circumference regardless of physical activity, total energy intake, and socioeconomic status.

“People with high indoor temperature tended to show higher abdominal circumference, with a statistically significant trend,” said Keigo Saeki, MD, PhD, of the Nara Medical University School of Medicine in Nara, Japan. “Compared with the lowest indoor temperature group with 82 cm abdominal circumference, people with 15°C to 20°C [indoor temperatures] and those with over 20°C [indoor temperature] showed significantly higher abdominal circumference by 2.4 cm and 2.8 cm, respectively.”

Dr Saeki presented the results during ENDO 2016.

Researchers hypothesized that adaptive thermogenesis induced by cold exposure may be useful for prevention from obesity due at least in part to cold-induced activation of brown adipose tissue.

Some experimental studies showed that cold exposure increases appetite and total energy intake, but Dr Saeki noted that it was unclear whether cold exposure is associated with abdominal obesity in real-world situations.

To test their hypothesis, researchers analyzed data on 1103 participants collected in the HEIJO-KYO study, a community-based cohort study. Participants were aged 72, on average. All stayed home in the daytime, and women made up roughly 53% of the study population.

From October 2010 to April 2014, researchers measured participants’ abdominal circumference and calculated mean indoor daytime temperature for each participant every 10 minutes for 1 48-hour period in the daytime during the same cold season. Indoor temperature was 16.1 ± 3.7°C and outdoor temperature was 8.7 ± 4.8°C.

Researchers then divided participants into 4 groups based on daytime indoor temperature and noted that those living in the warmest homes also had the largest abdomen circumference (see Table). 

Table. Indoor Temperature and Abdominal Circumference

Daily Indoor Temperature (Celsius) Abdominal Circumference
≤10°C (n=64) 81.3 cm (95% CI, 79.2-83.5)
10°C to 15°C (n=346) 83.4 cm (95% CI, 82.5-84.3)
15°C to 20°C (n=529) 84.2 cm (95% CI, 83.5-85.0)
≥20°C (n=164) 84.9 cm (95% CI, 83.6-86.3)

The National Institutes for Health says that an abdominal circumference greater than 102 cm for men and 88 cm for women is associated with a high risk for diseases such as type 2 diabetes, dyslipidemia, and hypertension.

“Even after statistical adjustment for other confounding factors such as age, gender, smoking and drinking habits, household income, education, physical activity, and energy intake, the trend stayed significant,” said Dr Saeki.

Reference

  1. Saeki K, Obayashi K, Kurumatani N. #FRI-608: Obesity and Indoor Cold Exposure: A Cross-Sectional Analysis of Population-Based Study. Presented at: ENDO 2016; April 1-4, 2016; Boston, MA.