No abstract

Eugonadal acromegalic patients have increased lumbar spine and femoral neck BMD compared to hypogonodal acromegalic patients and the general population, but it is reduced if patients have been hypogonadal.

No abstract

Fasting for 96 hours significantly alters the circadian rhythm of PTH(1-84) secretion by lowering the mean calcium concentration and attenuating the circadian rhythm of serum phosphate.

with an increase observed in concentrations of urinary hydroxyproline, pyridinoline, deoxypyridinoline, amino-and carboxy-terminal nonhelical (telopeptides) parts of type 1 collagen, all of which are produced during skeletal collagen degradation (box 3). The coupled increase in osteoblastic activity also results in elevated serum bone alkaline phosphatase, osteocalcin and procollagen extension peptides. Osteoblasts produce osteocalcin which is incorporated into the organic matrix of bone with a small proportion detectable in serum, and procollagen extension peptides are produced following the cleavage of procollagen to collagen.Urinary hydroxyproline, pyridinoline and deoxypyridinoline can be measured in both 24-hour and fasting (early morning) second voided urine collections. 24-Hour measurements eliminate diurnal influence, and fasting samples avoid fluctuations caused by dietary intake of collagen. A urine sample collected after an overnight fast at a standard time, approximately two hours after the first passage of urine that morning (second voided specimen), will eliminate both dietary and diurnal influences. Differences in lean body mass can be corrected by using the ratio to urinary creatinine (which is dependent on lean body mass). In most hospital outpatient clinics, total alkaline phosphatase remains the simplest and most sensitive marker of disease activity. In our centre, however, urinary markers are also used as early evidence of both response to treatment, and relapse. A total alkaline phosphatase level within the normal range may also be misleading, as many patients continue to complain of pain and have continuing activity on bone scintiscans. This is likely to be due to the fact that, despite a rise in their bone alkaline phosphatase level, total alkaline phosphatase (comprising bone, liver and gut isoenzymes) remains within the normal population range.Other biochemical changes include hypercalcaemia during immobilisation and occasional secondary hyperparathyroidism which has been attributed to a net excess in bone formation during the mixed osteolytic-osteosclerotic phase.13The usual age range of patients with Paget's disease does, however, mean that primary hyperparathyroidism is often detected. Haematological indices are not disturbed and as a reflection of its focal nature, Paget's disease of bone does not result in increased erythrocyte sedimentation rates or C-reactive protein concentrations. Clinical featuresIndirect evidence suggests that at least 70% of patients are asymptomatic and diagnosis is often made on the basis of incidental radiographs or elevated alkaline phosphatase concentrations on enzyme profiles. Paget's disease can, however, present in a variety of ways with skeletal, neurological and cardiovascular signs and symptoms (box 4).A common form of presentation is local bone pain, sometimes with obvious deformity, and local skin warmth due to increased bone microvasculature. The latter has been shown to be as much as six times that of normal bone.'4 The pain experienced is ofte...