Association between vitamin D receptor gene polymorphisms and Graves' disease: a systematic review and meta-analysis

PURPOSE

The pathogenesis of Graves' disease (GD) and orbitopathy (GO) is not completely elucidated. On the other hand, vitamin D receptor (VDR) gene polymorphisms have been associated with vulnerability to a plethora of chronic autoimmune diseases. The primary aim of this study was to synthesize evidence on the association between VDR gene polymorphisms and GD. Secondary aim was to investigate their association with GO.

METHODS

A comprehensive search was conducted in PubMed, CENTRAL and Scopus, up to December 8, 2018. Data were expressed as odds ratio (OR) with 95% confidence intervals (CI). Heterogeneity was quantified with I² index.

RESULTS

Ten studies were included in the qualitative and quantitative analysis. TT subtype of TaqI polymorphism was associated with an increased risk of GD compared with Tt and tt polymorphisms (OR: 1.42; 95% CI, 1.05-1.94, p = 0.025), whereas tt was associated with a lower risk of GD, compared with TT and Tt polymorphisms (OR: 0.79; 95% CI, 0.62-0.99, p = 0.043). No association was found for ApaI, BsmI, and FokI polymorphisms. The bb subtype of BsmI polymorphism was associated with a lower risk in Asian, but with a higher GD risk in Caucasian populations, compared with BB/Bb subtypes. No eligible study was found regarding the association between VDR gene polymorphisms and the risk of GO.

CONCLUSIONS

The TT subtype of the TaqI polymorphism was associated with a higher susceptibility for GD compared with Tt and tt. Regarding BsmI, the bb subtype was associated with increased GD risk in Caucasians, whereas it is protective in Asians.

Association between age at menopause and fracture risk: a systematic review and meta-analysis

PURPOSE

Early menopause (EM, age at menopause < 45 years) and premature ovarian insufficiency (POI, age at menopause < 40 years) are associated with an increased risk of osteoporosis. However, their association with increased fracture risk has not been established, with studies yielding conflicting results. The primary aim of this systematic review and meta-analysis was to synthesize studies evaluating the association between age at menopause and fracture risk. The secondary aim was to evaluate this effect concerning the site of fractures.

METHODS

A comprehensive search was conducted in PubMed, CENTRAL and Scopus, up to 31 January 2018. Data were expressed as odds ratio (OR) with 95% confidence intervals (CI). The I² index was employed for quantifying heterogeneity.

RESULTS

Eighteen studies were included in the qualitative and quantitative analysis (462,393 postmenopausal women, 12,130 fractures). Compared with women with age at menopause > 45 years, women with EM demonstrated higher fracture risk (OR 1.36, 95% CI 1.11-1.66, p < 0.002, I² 81.5%). Women with POI did not display any difference in fracture risk compared either with women with age at menopause > 40 (OR 1.23, 95% CI 0.72-2.09, p = 0.436, I² 62.5%) or >45 years (OR 0.54, 95% CI 0.22-1.29, p = 0.17, I² 0%). No difference was evident when a separate analysis was performed for vertebral, non-vertebral and hip fractures.

CONCLUSIONS

This is the first meta-analysis showing that EM is associated with increased fracture risk compared with normal age at menopause, without any distinct effect on the site of the fracture.

Early menopause and premature ovarian insufficiency are associated with increased risk of type 2 diabetes: a systematic review and meta-analysis

Objective/Design Menopausal transition has been associated with a derangement of glucose metabolism. However, it is not known if early menopause (EM, defined as age at menopause <45 years) or premature ovarian insufficiency (POI, defined as age at menopause <40 years) are associated with increased risk of type 2 diabetes mellitus (T2DM). To systematically investigate and meta-analyze the best evidence regarding the association of age at menopause with the risk of T2DM. Methods A comprehensive search was conducted in PubMed, CENTRAL and Scopus, up to January 31, 2018. Data are expressed as odds ratio (OR) with 95% confidence intervals (CI). The I 2 index was employed for heterogeneity. Results Thirteen studies were included in the qualitative and quantitative analysis (191 762 postmenopausal women, 21 664 cases with T2DM). Both women with EM and POI were at higher risk of T2DM compared with those of age at menopause of 45-55 years (OR: 1.15, 95% CI: 1.04-1.26, P = 0.003; I 2: 61%, P < 0.002 and OR: 1.50, 95% CI: 1.03-2.19, P = 0.033; I 2: 75.2%, P < 0.003), respectively). Similar associations emerged when women with EM and POI were compared with those of age at menopause >45 years (OR: 1.12, 95% CI: 1.01-1.20, P < 0.02; I 2: 78%, P < 0.001 and OR: 1.53, 95% CI: 1.03-2.27, P = 0.035; I 2: 78%, P < 0.001), respectively). Conclusions Both EM and POI are associated with increased risk of T2DM.

Efficacy of anti-osteoporotic medications in patients with type 1 and 2 diabetes mellitus: a systematic review

PURPOSE

Both type 1 (T1DM) and type 2 diabetes mellitus (T2DM) have been associated with bone fragility and increased fracture risk. However, little is known regarding the effect of anti-osteoporotic treatment on bone mineral density (BMD) and/or fracture risk in these patients. We aimed to systematically investigate the efficacy of anti-osteoporotic medications in patients with diabetes in comparison with non-diabetic subjects.

METHODS

MEDLINE and Scopus databases were searched (up to 31st October 2017).

RESULTS

Nine studies fulfilled the pre-defined inclusion criteria [patients with T2DM (n = 8) or either T1DM or T2DM (n = 1)]. Regarding fracture risk, five studies were identified. Alendronate demonstrated comparable vertebral anti-fracture efficacy in patients with and without diabetes (n = 2), whereas non-vertebral fracture risk was either the same (n = 1) or higher in diabetic patients (n = 1). Raloxifene also demonstrated comparable vertebral anti-fracture efficacy in both groups (n = 2), without any effect on non-vertebral fractures in either group. In one study, diabetic patients exposed to raloxifene demonstrated the same vertebral and non-vertebral fracture risk with non-diabetic patients. Teriparatide (n = 1) demonstrated the same non-vertebral fracture rates in both patients with and without T2DM. Regarding BMD, equal increases in spine BMD were observed with alendronate (n = 4), risedronate (n = 1), and teriparatide (n = 1). With respect to hip BMD, similar increases were observed with teriparatide (n = 1), whereas data regarding alendronate were controversial (n = 3). No eligible study was found for zoledronic acid, ibandronate, strontium ranelate, denosumab, or bazedoxifene.

CONCLUSIONS

The presence of diabetes does not alter anti-osteoporotic treatment response, regarding BMD increase and vertebral fracture risk reduction.