Determinants of Bone Mineral Density in Middle Aged Men: A Population-Based Study

Abstract

Osteoporosis is a growing health problem not only in women but also in men. To assess determinants of bone mineral density (BMD) at the spine and proximal femur, a randomly selected sample of 140 Finnish men aged 54-63 years was measured using fan beam dual-energy X-ray absorptiometry. Isometric muscle strength was measured using a computerized measurement system and cardiorespiratory fitness was assessed with maximal oxygen uptake (VO2 max) using breath-by-breath respiratory gas analyses during an incremental bicycle ergometer exercise. Intakes of calcium and energy were estimated using 4-day food records. Smoking habits and alcohol consumption were assessed from an interview and a 4 week diary, respectively. Isometric muscle strength of triceps and biceps brachii, extensors and flexors of thigh and rectus abdominis correlated significantly with BMD (r = 0.18-0.35, p = 0.02-0.000). Calcium intake correlated positively with femoral (r = 0.19-0.28, p = 0.03-0.003), but not with lumbar BMD. In addition, calcium intake adjusted for dietary energy content (mg/MJ) correlated with femoral BMD (r = 0.25-0.36, p = 0.03-0.000). Smoking had no effect on BMD, whereas alcohol intake correlated positively with BMD at L2-L4 (r=0.19, p = 0.031). In the multiple linear regression analysis adjusted calcium intake predicted BMD in every site measured, while strength of abdominal muscles predicted BMD at Ward's triangle and femoral neck. Body weight was a predictor of trochanteric BMD. Body height was the best predictor of lumbar and femoral neck area. We conclude that low dietary calcium intake, weak muscle strength and low body weight are risk factors for low BMD in men.

Risk factors for hip fractures in a middle-aged population: a study of 33,000 men and women

“…Previous studies have shown lower BMD in patients with trochanteric hip fractures compared with cervical hip fracture patients [19,20]. Since some significant risk factors for trochanteric hip fracture identified in this study are also risk factors for having low BMD, one could speculate that individuals suffering from trochanteric hip fracture may also have low BMD already in middle age [39][40][41][42]. Unfortunately, baseline assessment in this population was done before access to DXA (dual x-ray absorptiometry) and we are therefore unable to evaluate our speculations.…”

Risk factors for low BMD in healthy men age 50 years or older: a systematic review

“…A dose-response relationship with lifetime tobacco exposure (pack-years of smoking) was present in three studies [18,31,32], particularly in those who smoked in early adulthood [31], but was not present in two others [33,34]. Certain smoking subgroups may also be at increased risk: men with >20 pack years [32] and current smokers with low body weight (<75 kg) [32].…”

The relationship between body composition and bone mineral content: threshold effects in a racially and ethnically diverse group of men

“…Abundant epidemiological evidence links body composition to bone mass in older adults [17][18][19][20][21][22], and increased BMI has been linked to lower rates of osteoporosis and fracture [23]. Likewise, prospective investigations have demonstrated associations between declines in body size and both bone loss and increases in fracture risk [24][25][26].…”