The Extraglycemic Effect of SGLT-2is on Mineral and Bone Metabolism and Bone Fracture

Geriatric nutritional risk index as a predictor for fragility fracture risk in elderly with type 2 diabetes mellitus: A 9-year ambispective longitudinal cohort study

BACKGROUND & AIMS

The elderly are prone to fragility fractures, especially those suffering from type 2 diabetes mellitus (T2DM) combined with osteoporosis. Although studies have confirmed the association between GNRI and the prevalence of osteoporosis, the relationship between GNRI and fragility fracture risk and the individualized 10-year probability of osteoporotic fragility fractures estimated by FRAX remains unclear. This study aims to delve into the association between the GNRI and a fragility fracture and the 10-year probability of hip fracture (HF) and major osteoporotic fracture (MOF) evaluated by FRAX in elderly with T2DM.

METHODS

A total of 580 patients with T2DM aged ≥60 were recruited in the study from 2014 to 2023. This research is an ambispective longitudinal cohort study. All participants were followed up every 6 months for 9 years with a median of 3.8 years through outpatient services, medical records, and home fixed-line telephone interviews. According to the tertiles of GNRI, all subjects were divided into three groups: low-level (59.72-94.56, n = 194), moderate-level (94.56-100.22, n = 193), and high-level (100.22-116.45, n = 193). The relationship between GNRI and a fragility fracture and the 10-year probability of HF and MOF calculated by FRAX was assessed by receiver operating characteristic (ROC) analysis, Spearman correlation analyses, restricted cubic spline (RCS) analyses, multivariable Cox regression analyses, stratified analyses, and Kaplan-Meier survival analysis.

RESULTS

Of 580 participants, 102 experienced fragile fracture events (17.59%). ROC analysis demonstrated that the optimal GNRI cut-off value was 98.58 with a sensitivity of 75.49% and a specificity of 47.49%, respectively. Spearman partial correlation analyses revealed that GNRI was positively related to 25-hydroxy vitamin D [25-(OH) D] (r = 0.165, P < 0.001) and bone mineral density (BMD) [lumbar spine (LS), r = 0.088, P = 0.034; femoral neck (FN), r = 0.167, P < 0.001; total hip (TH), r = 0.171, P < 0.001]; negatively correlated with MOF (r = -0.105, P = 0.012) and HF (r = -0.154, P < 0.001). RCS analyses showed that GNRI was inversely S-shaped dose-dependent with a fragility fracture event (P < 0.001) and was Z-shaped with the 10-year MOF (P = 0.03) and HF (P = 0.01) risk assessed by FRAX, respectively. Multivariate Cox regression analysis demonstrated that compared with high-level GNRI, moderate-level [hazard ratio (HR) = 1.950; 95% confidence interval (CI) = 1.076-3.535; P = 0.028] and low-level (HR = 2.538; 95% CI = 1.378-4.672; P = 0.003) had an increased risk of fragility fracture. Stratified analysis exhibited that GNRI was negatively correlated with the risk of fragility fracture, which the stratification factors presented in the forest plot were not confounding factors and did not affect the prediction effect of GNRI on the fragility fracture events in this overall cohort population (P for interaction > 0.05), despite elderly females aged ≥70, with body mass index (BMI) ≥24, hypertension, and with or without anemia (all P < 0.05). Kaplan-Meier survival analysis identified that the lower-level GNRI group had a higher cumulative incidence of fragility fractures (log-rank, all P < 0.001).

CONCLUSION

This study confirms for the first time that GNRI is negatively related to a fragility fracture and the 10-year probability of osteoporotic fragility fractures assessed by FRAX in an inverse S-shaped and Z-shaped dose-dependent pattern in elderly with T2DM, respectively. GNRI may serve as a valuable predictor for fragility fracture risk in elderly with T2DM. Therefore, in routine clinical practice, paying attention to the nutritional status of the elderly with T2DM and giving appropriate dietary guidance may help prevent a fragility fracture event.

Effects of sodium-glucose cotransporter 2 inhibitors on bone metabolism in patients with type 2 diabetes mellitus: a systematic review and meta-analysis

BACKGROUND

Sodium glucose cotransporter 2 (SGLT2) inhibitors are widely used in type 2 diabetes mellitus (T2DM) therapy. The impact of SGLT2 inhibitors on bone metabolism has been widely taken into consideration. But there are controversial results in the study on the effect of SGLT2 inhibitors on bone metabolism in patients with T2DM. Therefore, we aimed to examine whether and to what extent SGLT2 inhibitors affect bone metabolism in patients with T2DM.

METHODS

A literature search of randomized controlled trials (RCTs) was conducted through PubMed, Web of Science, Embase, Cochrane databases, and Scopus from inception until 15 April 2023. Eligible RCTs compared the effects of SGLT2 inhibitors versus placebo on bone mineral density and bone metabolism in patients with T2DM. To evaluate the differences between groups, a meta-analysis was conducted using the random effects inverse-variance model by utilizing standardized mean differences (SMD).

RESULTS

Through screening, 25 articles were finally included, covering 22,828 patients. The results showed that, compared with placebo, SGLT2 inhibitors significantly increased parathyroid hormone (PTH, SMD = 0.13; 95%CI: 0.06, 0.20), and cross-linked C-terminal telopeptides of type I collagen (CTX, SMD = 0.11; 95%CI: 0.01, 0.21) in patients with T2DM, decreased serum alkaline phosphatase levels (ALP, SMD = -0.06; 95%CI: -0.10, -0.03), and had no significant effect on bone mineral density (BMD), procollagen type 1 N-terminal propeptide (P1NP), 25-hydroxy vitamin D, tartrate resistant acid phosphatase-5b (TRACP-5b) and osteocalcin.

CONCLUSIONS

SGLT2 inhibitors may negatively affect bone metabolism by increasing serum PTH, CTX, and decreasing serum ALP. This conclusion needs to be verified by more studies due to the limited number and quality of included studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO, identifier CRD42023410701.

SGLT2i improves kidney senescence by down-regulating the expression of LTBP2 in SAMP8 mice

Senescent kidney can lead to the maladaptive repairment and predispose age-related kidney diseases. Here, we explore the renal anti-senescence effect of a known kind of drug, sodium-dependent glucose transporters 2 inhibitor (SGLT2i). After 4 months intragastrically administration with dapagliflozin on senescence-accelerated mouse prone 8 (SAMP8) strain mice, the physiologically effects (lowering urine protein, enhancing glomerular blood perfusion, inhibiting expression of senescence-related biomarkers) and structural changes (improving kidney atrophy, alleviating fibrosis, decreasing glomerular mesangial proliferation) indicate the potential value of delaying kidney senescence of SGLT2i. Senescent human proximal tubular epithelial (HK-2) cells induced by H2 O2 also exhibit lower senescent markers after dapagliflozin treatment. Further mechanism exploration suggests LTBP2 have the great possibility to be the target for SGLT2i to exert its renal anti-senescence role. Dapagliflozin down-regulate the LTBP2 expression in kidney tissues and HK-2 cells with senescent phenotypes. Immunofluorescence staining show SGLT2 and LTBP2 exist colocalization, and protein-docking analysis implies there is salt-bridge formation between them; these all indicate the possibility of weak-interaction between the two proteins. Apart from reducing LTBP2 expression in intracellular area induced by H2 O2 , dapagliflozin also decrease the concentration of LTBP2 in cell culture medium. Together, these results reveal dapagliflozin can delay natural kidney senescence in non-diabetes environment; the mechanism may be through regulating the role of LTBP2.

Estudio del efecto del tratamiento con fármacos antidiabéticos sobre el metabolismo óseo

Objetivos

La prevalencia de la diabetes mellitus tipo 2 (DMT2) está aumentando de forma exponencial en todo el mundo, habiéndose comprobado que estos pacientes tienen mayor riesgo de presentar fracturas óseas, con respecto a la población sana, por lo que resulta de gran relevancia el conocimiento del efecto de los fármacos antidiabéticos sobre el metabolismo óseo.

Métodos

Estudio estadístico descriptivo, retrospectivo, de 106 pacientes en tratamiento con seis grupos de fármacos antidiabéticos: insulina, inhibidores de dipeptidilpeptidasa 4 (iDPP4), agonistas del receptor del péptido similar al glucagón tipo 1 (arGLP1), sulfonilureas, inhibidores del cotransportador de sodio-glucosa tipo 2 (iSGLT2) y pioglitazona, en los que se determinaron osteocalcina (OC), fosfatasa alcalina ósea (FAO) y telopéptido C-terminal del colágeno tipo 1 o beta-crosslaps (β-CTx).

Resultados

Se encontraron concentraciones más elevadas de β-CTx en los pacientes tratados con pioglitazona que en los tratados con iDPP4 (p=0,035), iSGLT2 (p=0,020) y con arGLP1 (p<0,001), siendo los pacientes tratados con arGLP1 los que presentaron las concentraciones más bajas de β-CTx.

Conclusiones

El tipo de tratamiento antidiabético recibido en pacientes que padecen DMT2 puede afectar el remodelado óseo. En nuestro estudio los pacientes que fueron tratados con pioglitazona mostraron las concentraciones más elevadas de β-CTx con respecto al resto de grupos de fármacos, lo cual parece indicar la conveniencia de evitar estos fármacos, sobre todo en mujeres postmenopáusicas con DMT2. Los fármacos arGLP1 presentaron los valores más bajos de β-CTx, por lo que podrían ejercer un efecto beneficioso sobre el metabolismo óseo.

Effects of antidiabetic drugs on bone metabolism

Objectives

The prevalence of diabetes mellitus type 2 (DMT2) is increasing exponentially worldwide. DMT2 patients have been found to be at a higher risk for bone fractures than the healthy population. Hence, improving our understanding of the impact of antidiabetic drugs on bone metabolism is crucial.

Methods

A descriptive, retrospective study involving 106 patients receiving six groups of antidiabetic drugs: insulin; dipeptidylpeptidase four inhibitors (DPP4i); glucagon-like peptide type 1 receptor agonists (GLP1ra); sulfonylureas; sodium-glucose cotransporter two inhibitors (SGLT2i); and pioglitazone, in which osteocalcin (OC), bone alkaline phosphatase (BAP) and C-terminal telopeptide of collagen type 1 or beta-crosslaps (β-CTx) were determined.

Results

β-CTx concentrations were higher in the patients treated with pioglitazone, as compared to patients treated with DPP4i (p=0.035), SGLT2i (p=0.020) or GLP1ra (p<0.001). The lowest β-CTx concentrations were observed in the patients treated with GLP1ra.

Conclusions

Bone remodeling is influenced by the type of antidiabetic drug administered to DMT2 patients. In our study, the patients who received pioglitazone showed higher β-CTx concentrations, as compared to patients treated with other types of antidiabetic drugs. This finding highlights the convenience of avoiding these drugs, especially in postmenopausal women with DMT2. GLP1ra drugs were associated with the lowest β-CTx concentrations, which suggests that these agents could exert beneficial effects on bone metabolism.

Improved Glycaemic Control and Nephroprotective Effects of Empagliflozin and Paricalcitol Co-Therapy in Mice with Type 2 Diabetes Mellitus

Herein, we measured the antidiabetic and nephroprotective effects of the sodium-glucose cotransporter-2 inhibitor (empagliflozin; SGLT2i) and synthetic active vitamin D (paricalcitol; Pcal) mono- and co-therapy against diabetic nephropathy (DN). Fifty mice were assigned into negative (NC) and positive (PC) control, SGLT2i, Pcal, and SGLT2i+Pcal groups. Following establishment of DN, SGLT2i (5.1 mg/kg/day) and/or Pcal (0.5 µg/kg/day) were used in the designated groups (5 times/week/day). DN was affirmed in the PC group by hyperglycaemia, dyslipidaemia, polyuria, proteinuria, elevated urine protein/creatinine ratio, and abnormal renal biochemical parameters. Renal SREBP-1 lipogenic molecule, adipokines (leptin/resistin), pro-oxidant (MDA/H2O2), pro-inflammatory (IL1β/IL6/TNF-α), tissue damage (iNOS/TGF-β1/NGAL/KIM-1), and apoptosis (TUNEL/Caspase-3) markers also increased in the PC group. In contrast, renal lipolytic (PPARα/PPARγ), adiponectin, antioxidant (GSH/GPx1/SOD1/CAT), and anti-inflammatory (IL10) molecules decreased in the PC group. Both monotherapies increased insulin levels and mitigated hyperglycaemia, dyslipidaemia, renal and urine biochemical profiles alongside renal lipid regulatory molecules, inflammation, and oxidative stress. While SGLT2i monotherapy showed superior effects to Pcal, their combination demonstrated enhanced remedial actions related to metabolic control alongside renal oxidative stress, inflammation, and apoptosis. In conclusion, SGLT2i was better than Pcal monotherapy against DN, and their combination revealed better nephroprotection, plausibly by enhanced glycaemic control with boosted renal antioxidative and anti-inflammatory mechanisms.

Evaluation of the Effect of Sodium-Glucose Cotransporter 2 Inhibition on Fracture Risk: Evidence From Mendelian Randomization and Genetic Association Study

This study aims to evaluate the causal effect of sodium-glucose cotransporter 2 (SGLT2) inhibition on bone mineral density (BMD), osteoporosis, and fracture risk using genetics. Two-sample Mendelian randomization (MR) analyses were performed utilizing two sets of genetic variants as instruments (six and two single-nucleotide polymorphisms [SNPs]) associated with SLC5A2 gene expression and glycated hemoglobin A1c levels. Summary statistics of BMD from the Genetic Factors for Osteoporosis consortium (BMD for total body, n = 66,628; femoral neck, n = 32,735; lumbar spine, n = 28,498; forearm, n = 8143) and osteoporosis (6303 cases, 325,717 controls) and 13 types of fracture (≤17,690 cases, ≤328,382 controls) data from the FinnGen study were obtained. One-sample MR and genetic association analyses were conducted in UK Biobank using the individual-level data of heel BMD (n = 256,286) and incident osteoporosis (13,677 cases, 430,262 controls) and fracture (25,806 cases, 407,081 controls). Using six SNPs as the instrument, genetically proxied SGLT2 inhibition showed little evidence of association with BMD of total body, femoral neck, lumbar spine, and forearm (all p ≥ 0.077). Similar results were observed using two SNPs as instruments. Little evidence was found for the SGLT2 inhibition effect on osteoporosis (all p ≥ 0.112) or any 11 major types of fracture (all p ≥ 0.094), except for a nominal significance for fracture of lower leg (p = 0.049) and shoulder and upper arm (p = 0.029). One-sample MR and genetic association analysis showed that both the weighted genetic risk scores constructed from the six and two SNPs were not causally associated with heel BMD, osteoporosis, and fracture (all p ≥ 0.387). Therefore, this study does not support an effect of genetically proxied SGLT2 inhibition on fracture risk. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

Management of Type 2 Diabetes in Frail Older Adults

Aging is one of the most important factors associated with the dramatic increase in the prevalence of type 2 diabetes mellitus (T2DM) globally. In addition to traditional micro- and macrovascular complications, diabetes mellitus (DM) in older adults is of great importance due to its independent relationship with frailty, which is defined as a decline in functional reserves and vulnerability to stressors. Frailty assessment enables the determination of biological age, thus predicting potential complications in older adults and identifying tailored treatment strategies. Although the latest guidelines have acknowledged the frailty concept and provided recommendations specific to this subgroup of older adults, frail older adults are particularly considered only as anorexic, malnourished people for whom relaxed treatment targets should be set. However, this approach bypasses other metabolic phenotypes in the context of diabetes and frailty. Recently, a spectrum of metabolic phenotypes in the context of frailty in DM was suggested, and the two edges of this spectrum were defined as "anorexic malnourished (AM)" and "sarcopenic obese (SO)." These two edges were suggested to require different strategies: Opposite to the AM phenotype requiring less stringent targets and de-intensification of treatments, tight blood glucose control with agents promoting weight loss was recommended in the SO group. Our suggestion is that, regardless of their phenotype, weight loss should not be the primary goal in DM management in older adults who are overweight or obese, because of the increased malnutrition prevalence in older adults suffering from DM compared with standard older adults. Furthermore, overweight older adults have been reported to have the lowest risk of mortality compared with other groups. On the other hand, obese older individuals may benefit from intensive lifestyle interventions including caloric restriction and regular exercise with the assurance of at least 1 g/kg/day high-quality protein intake. Besides metformin (MF), sodium-glucose cotransporter-2 inhibitors (SGLT-2i) or glucagon-like peptide-1 receptor agonists (GLP-1RA) should be considered in appropriate SO cases, due to high evidence of cardiorenal benefits. MF should be avoided in the AM phenotype due to their weight loss property. Although weight loss is not desired in AM phenotype, SGLT-2i may still be preferred with close follow-up in certain individuals demonstrating high cardiovascular disease (CVD) risk. Of note, SGLT-2i should be considered earlier in the diabetes treatment in both groups due to their multiple benefits, i.e., organ protective effects, the potential to reduce polypharmacy, and improve frailty status. The concept of different metabolic phenotypes in frail older adults with diabetes once again shows "one size fits all" cannot be applied in geriatric medicine, and a tailored, individualized approach should be adopted to get the highest benefit from treatments.

Mouse Models with SGLT2 Mutations: Toward Understanding the Role of SGLT2 beyond Glucose Reabsorption

The sodium–glucose cotransporter 2 (SGLT2) mainly carries out glucose reabsorption in the kidney. Familial renal glycosuria, which is a mutation of SGLT2, is known to excrete glucose in the urine, but blood glucose levels are almost normal. Therefore, SGLT2 inhibitors are attracting attention as a new therapeutic drug for diabetes, which is increasing worldwide. In fact, SGLT2 inhibitors not only suppress hyperglycemia but also reduce renal, heart, and cardiovascular diseases. However, whether long-term SGLT2 inhibition is completely harmless requires further investigation. In this context, mice with mutations in SGLT2 have been generated and detailed studies are being conducted, e.g., the SGLT2−/− mouse, Sweet Pee mouse, Jimbee mouse, and SAMP10-ΔSglt2 mouse. Biological changes associated with SGLT2 mutations have been reported in these model mice, suggesting that SGLT2 is not only responsible for sugar reabsorption but is also related to other functions, such as bone metabolism, longevity, and cognitive functions. In this review, we present the characteristics of these mutant mice. Moreover, because the relationship between diabetes and Alzheimer’s disease has been discussed, we examined the relationship between changes in glucose homeostasis and the amyloid precursor protein in SGLT2 mutant mice.

Fracture risks associated with sodium-glucose cotransporter-2 inhibitors in type 2 diabetes patients across eGFR and albuminuria categories: A population-based study in Hong Kong

AIMS

To evaluate major osteoporotic fracture (MOF) risk among type 2 diabetes patients treated with sodium-glucose cotransporter-2 inhibitors (SGLT2i) across eGFR and albuminuria categories.

METHODS

A population-based cohort of type 2 diabetes patients started on SGLT2i or dipeptidyl peptidase-4 inhibitors (DPP4i) during 2007-2020 was identified from Hong Kong Hospital Authority database. One-to-one propensity score matching was applied to match each SGLT2i user with one DPP4i user. The primary outcomes were 180- and 365-day risks of MOF. Cox proportional hazard regression models were used to estimate hazard ratios (HR).

RESULTS

A total of 28,696 patients (14,348 in each group) were included. Over 180-day follow-up, MOF occurred in 25 (0.17 %) SGLT2i users and 24 (0.17 %) DPP4i users (incidence of 4.07 and 3.63/1,000 person-years, respectively). At 365 days, MOF occurred in 43 (0.30 %) SGLT2i users and 44 (0.31 %) DPP4i users (incidence of 4.16 and 3.64/1,000 person-years, respectively). Risks of MOF were comparable between two groups at both 180 days (HR = 1.13, 95 %CI 0.65-1.98, P = 0.67) and 365 days (HR = 1.15, 95 %CI 0.75-1.75, P = 0.52). Subgroup analyses were consistent across age, sex, eGFR, albuminuria, or KDIGO categories.

CONCLUSIONS

Our study did not reveal a statistically significant increase in fracture risk with SGLT2i use compared with DPP4i among type 2 diabetes patients, across eGFR and albuminuria categories.

Cardiovascular-renal protective effect and molecular mechanism of finerenone in type 2 diabetic mellitus

Chronic kidney diseases (CKD) and cardiovascular diseases (CVD) are the main complications in type 2 diabetic mellitus (T2DM), increasing the risk of cardiovascular and all-cause mortality. Current therapeutic strategies that delay the progression of CKD and the development of CVD include angiotensin-converting enzyme inhibitors (ACEI), angiotensin II receptor blockers (ARB), sodium-glucose co-transporter 2 inhibitors (SGLT-2i) and GLP-1 receptor agonists (GLP-1RA). In the progression of CKD and CVD, mineralocorticoid receptor (MR) overactivation leads to inflammation and fibrosis in the heart, kidney and vascular system, making mineralocorticoid receptor antagonists (MRAs) as a promising therapeutic option in T2DM with CKD and CVD. Finerenone is the third generation highly selective non-steroidal MRAs. It significantly reduces the risk of cardiovascular and renal complications. Finerenone also improves the cardiovascular-renal outcomes in T2DM patients with CKD and/or chronic heart failure (CHF). It is safer and more effective than the first- and second-generation MRAs due to its higher selectivity and specificity, resulting in a lower incidence of adverse effects including hyperkalemia, renal insufficiency and androgen-like effects. Finerenone shows potent effect on improving the outcomes of CHF, refractory hypertension, and diabetic nephropathy. Recently studies have shown that finerenone may have potential therapeutic effect on diabetic retinopathy, primary aldosteronism, atrial fibrillation, pulmonary hypertension and so on. In this review, we discuss the characteristics of finerenone, the new third-generation MRA, and compared with the first- and second-generation steroidal MRAs and other nonsteroidal MRAs. We also focus on its safety and efficacy of clinical application on CKD with T2DM patients. We hope to provide new insights for the clinical application and therapeutic prospect.