Body mass index (BMI) and parameters of bone formation and resorption in postmenopausal women.

OBJECTIVES: Aim of this study was to evaluate increased body mass index (BMI) as an anthropometric factor, predisposing to lower rates of bone turnover or changes in bone balance after menopause. MATERIAL AND METHODS: For this purpose, we calculated BMI, and measured spinal (BMD(SP)) and femoral bone mineral density (BMD(FN)) and biochemical markers of bone formation (serum osteocalcin (S-OC), serum procollagen type I C propeptide (S-PICP), serum bone-specific alkaline phosphatase (S-B-ALP)) and resorption (urine N- and C-terminal cross-linking telopeptide of type I collagen (U-NTX-I and U-CTX-I), pyridinoline (U-PYD) and deoxypyridinoline (U-DPD)) in 130 healthy postmenopausal women, aged 46-85 years. Bone balance indices were calculated by subtracting z-scores of resorption markers from z-scores of formation markers, to evaluate bone balance. RESULTS: S-PICP ( r = -0.297, P = 0.002), S-OC ( r = -0.173, P = 0.05) and bone balance indices (zPICP-zDPD) and (zPICP-zPYD) were negatively correlated with BMI (r = -0.25, P = 0.01 and r = -0.25, P = 0.01 and r = -0.21, P = 0.037) and with BMD(SP) (r = -0.196, P = 0.032 and r = -0.275 and P = 0.022). Women were grouped according to their BMI, in normals (BMI < 25 kg/m2), overweight (BMI = 25-30 kg/m2, and obese (BMI > 30 kg/m2). Overweight and obese women had approximately 30% lower levels of S-PICP compared to normals (68.11 +/- 24.85 and 66.41 ng/ml versus 97.47 +/- 23.36 ng/ml, respectively; P = 0.0001). zPICP-zDPD, zPICP-zCTX-I and zPICP-zPYD were significantly declined in obese women compared to normals (P = 0.0072, 0.02 and 0.0028). CONCLUSIONS: We conclude that in postmenopausal women, BMI is inversely associated with levels of collagen I formation marker, serum PICP. In obesity formation of collagen I was reduced, in favor of degradation, but since this finding is not followed by simultaneous decrease in bone mineral density, it seems that increased body weight may have different effects on mature estrogen-deficient bone and extraskeletal tissues containing collagen I.

Cervical hip fractures do not occur in arthrotic joints. A clinicoradiographic study of 256 patients.

We studied endogenic factors for the occurrence of cervical hip fractures in 256 patients. 230 underwent hemiarthroplasty, and 26 were treated with internal fixation or without surgery. The condition of the fractured hip and of the ipsilateral knee, as well as the mobility of the patient before the fracture, were studied in all 256 patients. The removed femoral heads were examined, photographed and radiographs were taken with sensitive film. The acetabulum and the femoral head were macroscopically normal in all 230 cases and there was no radiographic evidence of arthrosis. 64% of the patients were fully mobile before the fracture, 34% were mobile with the aid of a cane and 2% were dependent. In 88%, the ipsilateral knee was normal both clinically and radiographically, and in 12%, there was moderate arthrosis. When comparing the mobility before the fracture and the condition of the ipsilateral hip and knee in 100 patients having a cervical fracture with 100 patients having a trochanteric fracture matched for age and sex, we found that a normal hip joint was sine qua non while a normal ipsilateral knee and a fully mobile individual were important additional conditions for the occurrence of a cervical hip fracture, instead of a trochanteric one, after a fall in an elderly person.

Possible predisposing factors for the second hip fracture.

Among 1685 patients who sustained a hip fracture at the island of Crete (Greece) in a 4-year period we found 106 patients with bilateral noncontemporary hip fractures. Pathologic hip fractures and fractures that emerged from high energy trauma were excluded. To investigate the possible factors predisposing to the later fracture in the sound hip, we studied these 106 patients and compared them with the 1579 patients who sustained a single hip fracture (control group). There was no significant difference between the mean age of the bilateral group at the time of the first hip fracture (78.3 +/- 7.4 years, range 52-94 years) and the mean age of the control group (77.3 +/- 11.9 years, range 50-101 years). We found no significant difference in the bone status between the two groups, using both lumbar spine dual photon absorptiometry (DXA) and calcaneus broadband ultrasound attenuation (BUA). Falls, which were the main cause of all the hip fractures, were much more common in the bilateral group. The second hip fracture was of the same location (trochanteric or cervical) in 92% of the trochanteric and 68% of cervical fractures and a tendency to greater displacement or instability was observed. Of the second hip fractures 75% happened in the first 48 months after the first one. The mean interval time was much longer (160 months) when a neck fracture was followed by a trochanteric one.