Characteristics of the female study participants by baseline age group and smoking categories.

<p>The Hordaland Health Study^a</p><p>Abbreviations: BMD, bone mineral density; BMI, body mass index.</p>a<p>Values are given as mean (standard deviation (SD)) for continuous variables and number (%) for categorical variables.</p>b<p>Never smoking, plasma cotinine levels <85 nmol/L and no self-reported previous smoking; former smoking, self-reported previous smoking and plasma</p><p>cotinine levels <85 nmol/L; moderate smoking, plasma cotinine levels between 85 and 1199 nmol/L; heavy smoking, plasma cotinine levels ≥1200 nmol/L.</p>c<p>Number of participants with data on femoral neck BMD, body soft tissue composition and plasma cotinine.</p>d<p><i>P</i>-value for trend across smoking categories.</p>e<p>Hip fractures from inclusion in 1998-2000 until December 31^st, 2009.</p><p>Total numbers may vary between variables due to varying numbers of missing data.