Osteoporosis in postmenopausal women in this decade: a bibliometric assessment of current research and future hotspots.

Postmenopausal osteoporosis (PMOP) has already become a major public health problem. However, there was no bibliometric analysis estimating the evolutionary process of PMOP research. PURPOSE: This study aimed to assess its scientific activity. METHODS: Publications on PMOP were retrieved from Science Citation Index-Expanded (SCI-E) of the Web of Science (WoS) from 2008 to 2018. VOSviewer software was used for data mining and visualization. The quantity of papers, number of citations, citation frequency per year, and H-index were assessed and compared among different countries, institutes, and researchers. RESULTS: A total of 11,142 papers were included and were cited 184,416 times. The USA contributed the most papers (3162), the most citations (83,270 times), and the highest H-index (115). Canada ranked first for the number of papers per million populations and per trillion GDP. Seven of the top ten funding agencies were industries. The key words were stratified into four clusters: cluster 1 ("basic research"), cluster 2 ("diagnosis"), cluster 3 ("treatment"), and cluster 4 ("others"). Average appearing years (AAY) of key words in cluster 1 were the largest compared to those in clusters 2 and 3. For hotspots, "miRNA" showed a relatively latest AAY of 2017.63, followed by "abaloparatide" and "adipokine". CONCLUSION: We concluded that the USA and Europe were the most productive regions on PMOP, with a high prevalence of articles supported by pharmaceutical companies. Key word focus gradually shifted from "diagnosis" to "treatment" and then to precision medicine orientated "basic research". It is recommended to pay attention to potential research hotspots, such as "miRNA," "abaloparatide," and "adipokine".

8th Pieter van Keep Memorial Lecture. Estrogen and bone: have we completed a full circle?

Estrogen therapy was considered first-line therapy for the prevention and treatment of postmenopausal osteoporosis in 1984. Evidence from a large, randomized clinical trial in 2002 proved the efficacy of estrogen in the prevention of all types of osteoporosis-related fractures. Ironically, estrogen was relegated to second-line therapy, based on perceived safety concerns. The historical background to these decisions is presented. It is argued that this decision is not a reasonable reflection of the available evidence, especially in comparison to other available drugs.

Historical milestones in the development of tibolone (Livial®).

For a new chemical entity, tibolone had a very long development period of 25 years before it was finally approved for the treatment of climacteric complaints. The reasons for this long development were its complex and fast metabolism and the poor standardization and sensitivity of analytical techniques and clinical methods. In the beginning of the new millennium, the results of primate studies and dose-finding studies in early postmenopausal women showed that tibolone had clear tissue-selective effects: it prevented hot flushes and bone loss, which are estrogen-related effects, while the estrogen-sensitive organs like breast and endometrium were not stimulated. In tissue, measurements of tibolone metabolites revealed that estrogenic metabolites were present in brain, but these metabolites were found as inactive conjugates in breast and endometrium. Attempts to find new indications for tibolone in large clinical trials failed because these studies were performed in elderly women who had already past the menopause many years ago and so unexpected side-effects became apparent due to altered metabolism and gene activation.

Biographical sketch: Fuller Albright, MD 1900-1969.

This biographical sketch on Fuller Albright corresponds to the historic text, The Classic: The Metabolic Effects of Steroid Hormones in Osteoporosis, available at DOI 10.1007/s11999-011-1832-z .

Age-related cortical bone loss in women from a 3rd-4th century AD population from England.

Age-dependent cortical bone loss in adult females from a skeletal assemblage from 3rd-4th century AD England was studied using metacarpal radiogrammetry. Results showed reduced peak cortical bone thickness compared with modern subjects, and the magnitude of cortical bone loss in older females compared with their younger counterparts was greater than that documented for a modern reference population. An elevated prevalence of fractures classically associated with osteoporosis was also observed in the over-50-year cohort. The severity of osteoporosis in this group is difficult to explain in terms of extraneous factors relating to 3rd-4th century lifestyles. Given the important genetic component in osteoporosis, the results may indicate some inherent susceptibility in this particular population to the disease, and ways in which this possibility might be further explored are suggested.

[Age and sex specific differences in bone density of 4,000-year-old individuals. Bone density measurement of early Bronze Age femurs from excavations in Unterhautzenthal, Lower Austria]. / Alters- und geschlechtsspezifische Unterschiede der Knochendichte von 4000 Jahre alten Individuen. Knochendichtemessung an frühbronzezeitlichen Femora von Ausgrabungen aus Unterhautzenthal, NO.

Bone density measurements of 14 individuals (early Bronze Age, 2200-1600 BC), analyzed by dual-energy absorptiometry, showed a distinct difference between women and men. In men, there was a high bone density (+17.9%-0.290 g/cm2 difference). In females, a constant decrease in bone density was found after the age of 20-25 years (from 1.2 g/cm2 at 20 years to 0.8 g/cm2 at 40 years of age). With caution, the results are comparable with those of the present time.

Age- and sex-dependent cancellous bone changes in a 4000y BP population.

We studied cancellous bone loss in a 4000y BP population, using several methods designed to detect age-related changes, in order to investigate the pattern of cancellous bone loss in this ancient population and to compare the results deriving from different methods used on identical specimens. We used 10-mm sections of fourth lumbar vertebral bodies and left femoral necks of 18 individuals of both sexes with estimated ages from 20 to 60 years of a 4000y BP bronze-age population. Stereoscopic photographs were used for three-dimensional analysis and trabecular number (TN) counting. After embedding, the following parameters were measured in different image analysis systems using plane parallel block samples: bone mineral density (BMD) in water by DEXA, and by evaluation of standardized radiographic images; fractional bone volume (BV/TV) in backscattered electron images of the trabecular surface layer and in optical images of trabeculae in a surface-stained layer; and trabecular bone pattern factor (TBPf) in the latter images. There was a high correlation between the results of morphological methods for measuring fractional bone volume. Reasonable correlations were found between the x-ray photon methods and poor correlations between these and the morphological methods. These poor correlations may be due to the diagenetic substitution occurring in archaeological skeletons, which would strongly influence x-ray-based density measurements. However, all the methods demonstrated that the most dramatic loss of quantity and quality in cancellous bone occurred in females between 40 and 60 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Fuller Albright. His concept of postmenopausal osteoporosis and what came of it.

Fifty years ago Albright contributed the following to understanding osteoporosis: (1) He recognized it as a deficiency of formation, not of mineralization of bone matrix; (2) he observed that 40 of 42 patients with osteoporosis before age 65 were women past menopause or young women postoophorectomy; (3) he concluded that estrogen stimulates osteoblasts (a conclusion later challenged); (4) he demonstrated by metabolic balance studies that estrogen causes a positive calcium balance in postmenopausal osteoporosis; (5) he introduced periodic progesterone to prevent or treat endometrial hyperplasia from prolonged estrogen therapy; and (6) he showed that long-term therapy arrested vertebral damage and height loss in postmenopausal osteoporosis and prevented them if started early. Since Albright's time, more sensitive methods of assessing bone density have replaced conventional roentgenograms. Some large scale trials of estrogen have indicated increased bone density and fewer fractures. Unopposed estrogen increases risk of endometrial cancer and decreases mortality from other cancers, myocardial infarction, stroke, and osteoporosis. Trials of calcitonin, diphosphonates, fluoride, vitamin D, and high calcium intake have not proved more effective than estrogen.