Antiresorptive Versus Anabolic Therapy in Managing Osteoporosis in People with Type 1 and Type 2 Diabetes

The diabetic neuropathy and bone mineral density in type 2 diabetes mellitus: a cross-sectional and meta-analytic study

Diabetic neuropathy (DN) is a common complication of type 2 diabetes mellitus (T2DM), yet its impact on bone mineral density (BMD) remains unclear. This study combines cross-sectional and meta-analytic methods to comprehensively explore the relationship between DN and osteoporosis in T2DM patients. The cross-sectional study included 523 T2DM patients, classified into DN and non-DN groups. BMD was measured using dual-energy X-ray absorptiometry (DXA), and multivariate analysis identified osteoporosis-related factors. The meta-analysis included studies published from 1999 to 2021, comparing BMD between patients with and without DN. The results showed that while significant differences in clinical characteristics and biochemical indices (such as age, HbA1c, and 25(OH) vitamin D levels) were observed between the groups, no significant association between DN and osteoporosis was found after adjusting for covariates like body mass index and blood pressure. Additionally, the meta-analysis confirmed no significant impact of DN on BMD across skeletal sites, including the lumbar spine, hip, and femoral neck. These findings suggest that while DN may indirectly affect bone health through alterations in bone metabolism (such as bone formation markers), its direct impact on BMD is limited. The study's limitations include its cross-sectional design, which restricts causal inference, and retrospective data collection, underscoring the need for prospective studies to further elucidate the mechanisms behind DN's effects on bone health. These results highlight the complex interplay of factors influencing osteoporosis risk in T2DM and underscore the importance of a multifactorial approach to bone health management in this population.

Hypothyroidism correlates with osteoporosis: potential involvement of lipid mediators

Background

Observational studies have demonstrated a correlation between thyroid dysfunction and osteoporosis (OP); however, the underlying causality has yet to be fully elucidated.

Methods

The necessary dataset was sourced from public databases. Initially, instrumental variables (IVs) were selected based on three primary hypotheses. Subsequently, Cochran's Q test was employed to exclude IVs exhibiting heterogeneity. The MR-PRESSO test and the leave-one-out sensitivity test were further applied to detect potential pleiotropy. Inverse variance was utilized for the analysis. This study primarily utilized the inverse variance weighted (IVW) model for Mendelian analysis. Since Type 1 diabetes mellitus can also contribute to the development of osteoporosis, this study additionally employed multivariate Mendelian analysis. Furthermore, 249 circulating metabolites were selected for mediation analysis in the Mendelian randomization framework.

Results

In this study, the two-sample Mendelian randomization (MR) analysis primarily employed the random-effects IVW model and demonstrated a causal relationship between hypothyroidism (OR = 1.092, 95% CI: 1.049-1.137, p < 0.001) and hyperthyroidism (OR = 1.080, 95% CI: 1.026-1.137, p = 0.003) with the risk of OP. No causal relationships were identified between FT3, FT4, TSH, and the risk of OP (p > 0.05). The results of the multivariate Mendelian randomization (MVMR) analysis indicated that hyperthyroidism was no longer a risk factor for OP (OR = 0.984, 95% CI: 0.918-1.055, p = 0.657), whereas hypothyroidism persisted as a risk factor (OR = 1.082, 95% CI: 1.021-1.147, p = 0.008). The mediated Mendelian randomization analysis revealed that hypothyroidism may exert an indirect effect on OP via triglycerides in large VLDL, mediating approximately 2.47% of the effect.

Conclusion

This study identifies a potential link between hypothyroidism and OP, possibly mediated indirectly via triglyceride levels in large VLDL. Further investigations are required to elucidate the direct or indirect causal mechanisms underlying this association.

Microvascular disease and early diabetes onset are associated with deficits in femoral neck bone density and structure among older adults with longstanding type 1 diabetes

Adults with type 1 diabetes (T1D) have increased hip fracture risk, yet no studies have assessed volumetric bone density or structure at the hip in older adults with T1D. Here, we used previously collected 3D CT scans of the proximal femur from older adults with longstanding T1D and non-diabetic controls to identify bone deficits that may contribute to hip fracture in T1D. In this retrospective cohort study, we identified 101 adults with T1D and 181 age-, sex-, and race-matched non-diabetic controls (CON) who received abdominal or pelvis CT exams from 2010 to 2020. Among adults with T1D, 33 (33%) had mild-to-moderate nephropathy, 61 (60%) had neuropathy, and 71 (70%) had retinopathy. Within the whole cohort, adults with T1D tended to have lower FN density, though differences did not reach statistical significance. The subset of the T1D group who were diagnosed before age 15 had lower total BMC (-14%, TtBMC), cortical BMC (-19.5%, CtBMC), and smaller Ct cross-sectional area (-12.6, CtCSA) than their matched controls (p<.05 for all). Individuals with T1D who were diagnosed at a later age did not differ from controls in any bone outcome (p>.21). Furthermore, adults with T1D and nephropathy had lower FN aBMD (-10.6%), TtBMC (-17%), CtBMC (-24%), and smaller CtCSA (-15.4%) compared to matched controls (p<.05 for all). Adults with T1D and neuropathy had cortical bone deficits (8.4%-12%, p<.04). In summary, among older adults with T1D, those who were diagnosed before the age of 15 yr, as well as those with nephropathy and neuropathy had unfavorable bone outcomes at the FN, which may contribute to the high risk of hip fractures among patients with T1D. These novel observations highlight the longstanding detrimental impact of T1D when present during bone accrual and skeletal fragility as an additional complication of microvascular disease in individuals with T1D.

Skeletal Fragility in Adult People Living With Type 1 Diabetes

Advances in the management of people with type 1 diabetes (T1D) led to longer life expectancy, but with it an aging population with age-associated conditions. While macrovascular and microvascular complications are widely recognized, bone fragility has received considerably less attention, although fractures lead to high morbidity and mortality. Hip fracture risk is up to sixfold higher in T1D than in nondiabetic controls and significantly higher than in type 2 diabetes. Hip fractures occur at a younger age, and the consequences are worse. The risk of nonvertebral fractures is also significantly increased. Altered bone quality is a major underlying mechanism. Areal BMD measured by DXA underestimates fracture risk. BMD testing is recommended in T1D patients with poor glycemic control and/or microvascular complications. Trabecular bone score is mildly reduced, and its ability to predict fractures in T1D is unknown. Bone turnover markers, particularly procollagen type 1 N-terminal propeptide, are suppressed and do not predict fracture risk in T1D. T1D-related risk factors for fractures include disease onset at age <20 years, longer disease duration, HbA1c ≥8%, hypoglycemic episodes and microvascular complications. Data regarding the efficacy of therapeutic interventions to prevent or treat skeletal fragility in T1D is scant. Adequate calcium and vitamin D intake and fall prevention are recommended. Antiosteoporosis therapies are recommended in T1D patients with previous hip or vertebral fragility fracture, more than 1 other fragility fracture, BMD T-score < -2.5 at the femoral neck or spine, and increased FRAX score. Fracture risk assessment needs to be part of the management of people with T1D.