Genetics of osteoarticular disorders, Florence, Italy, 22-23 February 2002

Management of Osteoporosis in Men: A Narrative Review

Male osteoporosis is a still largely underdiagnosed pathological condition. As a consequence, bone fragility in men remains undertreated mainly due to the low screening frequency and to controversies in the bone mineral density (BMD) testing standards. Up to the 40% of overall osteoporotic fractures affect men, in spite of the fact that women have a significant higher prevalence of osteoporosis. In addition, in males, hip fractures are associated with increased morbidity and mortality as compared to women. Importantly, male fractures occur about 10 years later in life than women, and, therefore, due to the advanced age, men may have more comorbidities and, consequently, their mortality is about twice the rate in women. Gender differences, which begin during puberty, lead to wider bones in males as compared with females. In men, follicle-stimulating hormones, testosterone, estrogens, and sex hormone-binding levels, together with genetic factors, interact in determining the peak of bone mass, BMD maintenance, and lifetime decrease. As compared with women, men are more frequently affected by secondary osteoporosis. Therefore, in all osteoporotic men, a complete clinical history should be collected and a careful physical examination should be done, in order to find clues of a possible underlying diseases and, ultimately, to guide laboratory testing. Currently, the pharmacological therapy of male osteoporosis includes aminobisphosphonates, denosumab, and teriparatide. Hypogonadal patients may be treated with testosterone replacement therapy. Given that the fractures related to mortality are higher in men than in women, treating male subjects with osteoporosis is of the utmost importance in clinical practice, as it may impact on mortality even more than in women.

Field synopsis and synthesis of genetic association studies in osteoarthritis: the CUMAGAS-OSTEO information system

A comprehensive and systematic assessment of the current status of genetic association studies (GAS) for osteoarthritis was conducted. Data from 327 GAS involving 187 distinct genetic variants were analyzed and cataloged in CUMAGAS-OSTEO, a Web-based information system (http://biomath.med.uth.gr) that allows the retrieval and synthesis of data from GAS on osteoarthritis. In individual studies, 66 variants (mostly single nucleotide polymorphisms) showed significant associations with osteoarthritis risk. For 19 variants, the association was significant at P < 0.01, with an increased risk greater than 30%. Only 2.4% of studies had statistical power greater than 50% to detect a modest genetic effect. Nineteen variants were investigated by 4 or more studies, and their results were subjected to meta-analysis. Significant associations were derived for 2 variants (GDF5 rs143383, LRCH1 rs912428) in the main meta-analysis and for 2 other variants (TXNDC3 rs4720262, ESR1 rs2234693) in subgroup analysis by ethnicity or osteoarthritic body site. Heterogeneity ranged from none to high. In general, there was consistency of genetic effects across ethnic groups and body sites, and there was no differential magnitude of effect in large studies versus small studies. CUMAGAS-OSTEO may be a useful tool for identifying pertinent gene-osteoarthritis associations and providing an updated summary of risk effects.

Are bone losers distinguishable from bone formers in a skeletal series? Implications for adult age at death assessment methods

Clinical studies indicate that genetic factors play a crucial role in primary osteoarthritis and osteoporosis. In addition, it has been suggested that these two diseases are inversely related. Within a population, one can find two sub-groups: the "bone formers" and the "bone losers". The changes to the joint surfaces used to assess adult age at death are related to the loss of bone substance and to bone formation (osteophytes). The modification of these indicators with age differs between bone formers and bone losers. Therefore, age-at-death assessment methods should make use of two standards, one for each sub-group. A preliminary study examining the possibility of distinguishing those who lose cortical bone from those who show signs of bony formation was conducted on a series of skeletons from Portugal, dating to the end of 19th century and the beginning of the 20th. Bone loss was evaluated using the cortical index (CI) of the second metacarpal on X-rays. The presence of osteophytes on dry bones was assessed macroscopically. Our study indicates that females' CI decreases with age, whereas the presence of osteophytes is strongly related to age in both sexes. But we have failed to find the inverse relationship between osteophytes and bone loss. Our study, however, shows that within a population, some individuals are not likely to develop osteophytes.