Table 1.

Distribution of sex-specific quartiles^¶ of total hip aBMD, by selected characteristics at study baseline (N=2,065), the Johnston County Project

	Total Hip aBMD
Characteristics	Q1 (low) % or Mean (SE) N=517	Q2 (intermediate low) % or Mean (SE) N=516	Q3 (intermediate high) % or Mean (SE) N=517	Q4 (high) % or Mean (SE) N=515	P-value*
Age, years	65.3 (0.6)	61.0 (0.4)	58.0 (0.4)	56.6 (0.5)	<0.01
Race					<0.01
White	89.8	80.0	79.1	56.0
Black	10.2	20.0	20.9	44.0
Attended college	25.3	24.9	22.3	17.6	0.03
BMI	26.7 (0.2)	29.3 (0.2)	31.5 (0.2)	34.1 (0.3)	<0.01
Smoking history†					<0.01
Never	48.7	54.5	60.1	58.6
Former	30.6	26.2	24.2	20.5
Current	20.7	19.3	15.7	20.9
Meets HHS physical activity recommendations¶	49.8	50.3	62.5	55.7	<0.01
History of bisphosphonate use	9.1	6.5	2.3	2.5	<.01
History of steroid use	22.5	25.4	28.9	34.6	<.01
History of knee injury	19.1	22.7	24.4	25.0	0.08
History of hip injury	5.7	5.6	6.2	5.6	0.96

Abbreviations: aBMD, areal bone mineral density; BMI, body mass index; HHS, Health and Human Services;

^¶Total hip aBMD quartiles among women (g/cm²): Q1: 0.4574–0.7659; Q2: 0.7660–0.8726; Q3: 0.8732–0.9818; Q4: 0.9824–1.4382

^¶Total hip aBMD quartiles among men (g/cm²): Q1: 0.4387– 0.8793; Q2: 0.8805– 0.9974; Q3:0.9979– 1.1006; Q4: 1.1020–1.6039

^*P-values were derived from chi-square tests of independence (testing whether any proportions differed) and ANOVA (testing whether any means differed)

^†Participants who answered “yes” to the question “Have you EVER smoked at least 100 cigarettes (or 5 packs) in your entire life?”, but answered “no” to the question “Do you smoke cigarettes now?” were considered to be former smokers. Those who answered ‘yes” to the latter question were considered to be current smokers.

^¶Participants who met HHS physical activity guidelines of ≥150 minutes of moderate-equivalent physical activity per week