Combined body mass index and abdominal obesity, lifestyle and health in a Norwegian adult population: a cross-sectional study

Aim: This study aimed to determine the prevalence of combined body mass index and waist circumference (BMI-WC) disease risk categories in a Norwegian adult population aged 18–51 years and describe selected health indicators (lifestyle factors, medical conditions, self-perceived health and high sensitive serum C-reactive protein (hs-CRP)) within these categories. Subjects and methods: A sample of 1318 adults (aged 18–51 years) answered a comprehensive questionnaire covering lifestyle factors, medical conditions, self-perceived health and background variables in the population-based cross-sectional Telemark study, Norway, 2014–2015. BMI, WC and hs-CRP were determined as part of a broader medical examination. Four combined BMI-WC risk categories were constructed, based on recommendations provided by the US National Institutes of Health (NIH), and associations with health indicators examined using multiple logistic regression analyses. Results: More than half of the participants represented combined BMI-WC categories with elevated disease risk (27% with increased risk, 11% with high risk and 19% with very high risk). Unfavourable health indicators (low physical activity, cardiovascular disease (CVD) history, physician-diagnosed high blood pressure and diabetes, lowered self-perceived health and elevated hs-CRP) increased in line with BMI-WC disease risk. Associations were observed independent of gender, age, education level and residential area. Conclusion: The findings highlight the importance of using both BMI categories and WC for personalised assessment of obesity-related risk and need for follow-up. The findings are considered relevant to public health intervention programmes targeting adults with overweight and obesity. Follow-up studies are warranted to study morbidity development in the BMI-WC risk categories.