The population attributable risk of nutrition and lifestyle on hip fractures

Norway is among the countries with the highest incidence of hip fractures, and how to reduce this incidence is a major public health concern.

The population attributable risk (PAR), which measures the portion of hip fracture incidences in the population that can be attributed to an exposure if there is a causal relationship, was assessed for the exposure to excessive alcohol consumption, being underweight, low calcium from dairy products, low physical activity and current tobacco smoking. The risk ratio (RR) of the exposures summarized from systematic reviews and meta-analyses, as well as their prevalence from national statistics or Norwegian population-based studies, were used to estimate PARs.

Low physical activity and current tobacco smoking had the highest RR for hip fractures, with 1.65 (95% CI 1.50-1.81) and 1.52 (95% CI 1.41-1.63). Low physical activity had the highest prevalence in the population (27.4%) and the highest PAR (0.151), followed by tobacco smoking (PAR = 0.081) and excessive alcohol consumption (PAR = 0.01). By comparison, being underweight and low calcium from dairy products had negligible PAR estimates.

From a public health perspective, increased daily physical activity is the most promising intervention to reduce the incidence of hip fractures. Reduced smoking and alcohol consumption are of relevance, but other health risks related to these exposures are of greater public health concern. Low body weight and nutritional calcium from dairy products seem to be of less importance.