Daily Endocrinology Research Analysis
Analyzed 45 papers and selected 3 impactful papers.
Summary
Three papers advance endocrinology and metabolic medicine today: rare APOB variants markedly increase risk for advanced MASLD and hepatocellular carcinoma; baseline renal functional reserve robustly predicts the acute GFR dip to empagliflozin in randomized mechanistic trials; and metabolic bariatric surgery in youth with T2D reprograms renal metabolism (AMPK/FOXO3 up, mTORC1 and JAK-STAT down), aligning molecular changes with improved kidney structure and function.
Research Themes
- Genetic risk stratification in metabolic liver disease
- Personalized nephro-metabolic therapy using physiologic biomarkers
- Translational single-cell and proteomic insights after metabolic surgery
Selected Articles
1. Carriage of rare APOB variants predisposes to severe steatotic liver disease and hepatocellular carcinoma.
Across clinical, family, and biobank cohorts, rare APOB variants were strongly enriched in advanced MASLD and increased risks of cirrhosis and hepatocellular carcinoma, despite lower circulating lipids. ApoB100-specific variants exerted greater hepatic lipid effects and appeared protective against coronary artery disease, underscoring divergent cardiohepatic trade-offs and the potential utility of APOB genotyping for risk stratification.
Impact: This large, multi-cohort genetic study links rare APOB variants to progression and cancer in MASLD, reframing risk in patients with low LDL but high liver risk. It provides actionable genomics for surveillance and mechanistic insights into VLDL versus chylomicron pathways.
Clinical Implications: Consider APOB genotyping in MASLD to identify individuals at heightened risk for fibrosis progression and HCC, even when LDL-C is low; surveillance and counseling should reflect cardiohepatic trade-offs.
Key Findings
- Rare APOB variants were enriched in advanced MASLD (OR 13.8, 95% CI 2.7-70.7; P=0.002).
- Meta-analysis showed increased risk for cirrhosis (OR 1.82) and hepatocellular carcinoma (OR 3.53) across ancestries.
- Carriers had lower circulating lipids but higher MASLD activity and fibrosis.
- ApoB100-specific variants had ~3-fold greater impact on hepatic lipid metabolism and were protective against coronary artery disease.
- Distinct effects of impaired VLDL vs chylomicron secretion on liver outcomes were observed.
Methodological Strengths
- Integration of multiple cohorts (clinical case-control, family-based, MVP, UK Biobank) with cross-ancestry meta-analysis
- Concordant phenotyping (lipids, activity scores, fibrosis) and segregation analysis supporting causality
Limitations
- Observational design limits causal inference despite strong associations
- Rare variant ascertainment and heterogeneity across datasets may introduce selection and measurement biases
Future Directions: Prospectively test APOB-guided risk stratification for MASLD surveillance; perform functional studies dissecting ApoB100 vs ApoB48 variant effects and evaluate therapeutic modulation of lipoprotein secretion pathways.
BACKGROUND: MASLD has a substantial inherited component. Rare variants in Apolipoprotein B gene (APOB) have been implicated in susceptibility to liver steatosis, but their role in disease progression and outcomes is unclear. METHODS: We investigated APOB rare variants in a case-control cohort of people with advanced MASLD vs. healthy controls (n = 510/261), a family-based study (n = 43 and literature meta-analysis), the Million Veteran Program cohort (MVP, n = 94,885) and the UK Biobank (UKBB, n = 417,657). RESULTS: In the clinical cohort, APOB variants were enriched in people with advanced MASLD (OR 13.8, 95% c.i. 2.7-70.7, P = 0.002) and associated with lower circulating lipids, but higher MASLD activity and fibrosis (P < 0.05). In the family study, APOB variants segregated with hepatic steatosis and fibrosis (P < 0.05). Cross-ancestry meta-analysis of the study cohorts yielded pooled ORs for cirrhosis and hepatocellular carcinoma of 1.82, 95% c.i. 1.33-2.49 and 3.53, 95% c.i. 2.09-5.98, respectively. Variants affecting specifically ApoB100 had a three-fold greater impact on hepatic lipid metabolism compared to those impairing also ApoB48 and were specifically protective against coronary artery disease (P < 0.05). Variants affected cirrhosis risk similarly, but ApoB48/100 had a larger impact on hepatocellular carcinoma (P < 0.05). CONCLUSIONS: Rare APOB variants predispose to advanced MASLD and HCC, with distinct contributions from disrupted VLDL and chylomicrons secretion. These findings highlight the interplay between hepatic and intestinal lipid handling, suggesting that APOB genotyping may enhance MASLD risk stratification and case identification. FUNDING: European Union, Italian Ministry of Health, Swedish Research Council, Veteran health administration, NIH.
2. Renal functional reserve predicts GFR response to empagliflozin in RENALIS and RACELINES clinical trials.
Pooling two randomized, double-blind mechanistic trials, the study shows that postprandial renal functional reserve strongly predicts the acute GFR dip after 8 weeks of empagliflozin, but not with linagliptin or sulfonylureas. Gold-standard mGFR/ERPF measurements and intrarenal hemodynamic modeling support RFR as a physiologic biomarker to personalize SGLT2 inhibitor therapy.
Impact: Introduces an immediately measurable physiologic biomarker (RFR) that predicts empagliflozin’s hemodynamic effect, linking an early GFR dip to long-term renal benefit and enabling treatment selection.
Clinical Implications: A standardized postprandial RFR test could help identify patients most likely to benefit from SGLT2 inhibitors (empagliflozin), guiding therapy selection and counseling about expected GFR changes.
Key Findings
- Protein-rich meal increased mGFR by +7.3±1.7 mL/min/1.73m2 (P<0.001) and ERPF by +44.3±14.9 mL/min/1.73m2 (P=0.005), with reduced renal vascular resistance.
- Empagliflozin decreased mGFR after 8 weeks (−9.1±3.2 mL/min/1.73m2; P=0.016), while linagliptin had no effect; sulfonylurea showed a non-significant trend.
- Baseline meal-induced mGFR change correlated strongly with empagliflozin-induced mGFR change (r=0.88; P<0.001), but not with linagliptin or sulfonylureas.
Methodological Strengths
- Randomized, double-blind, parallel-group mechanistic trials with pooled analysis
- Gold-standard measurements of mGFR (inulin/iohexol) and ERPF (PAH), with intrarenal hemodynamic modeling
Limitations
- Short duration (8 weeks) and modest sample size limit clinical outcome inference
- Requires specialized clearance testing; generalizability to routine care and diverse populations remains to be shown
Future Directions: Validate RFR cutoffs in larger, pragmatic trials, integrate simpler surrogates of RFR, and test RFR-guided SGLT2i initiation on long-term renal outcomes.
BACKGROUND AND HYPOTHESIS: Glomerular hyperfiltration is common in type 2 diabetes (T2D) and may reflect reduced nephron number and/or perturbed intrarenal hemodynamics. Renal functional reserve (RFR), the capacity to increase GFR with physiological stimuli (e.g. a meal), may help reveal single-nephron hyperfiltration in patients with preserved baseline whole-kidney GFR. We hypothesized that reduced postprandial RFR predicts the acute hemodynamic GFR-response in T2D to the sodium-glucose co-transporter-2 inhibitor empagliflozin, but not to the dipeptidyl-peptidase-4 inhibitor linagliptin or a sulfonylurea. METHODS: This analysis pooled data from two 8-week randomized, double-blind, parallel-group mechanistic trials, encompassing 71 T2D patients with preserved whole-kidney GFR (mean ± SD age 65 ± 7 yrs, BMI 30.4 ± 3.9 kg/m2, HbA1c 7.8 ± 1.0% [61.6 ± 11.0 mmol/mol], GFR 86.5 ± 17.6 mL/min/1.73m2). Patients received empagliflozin (10 mg; N = 20), linagliptin (5 mg; N = 27) or sulfonylurea (glimepiride 1 mg, or gliclazide 30 mg; N = 24), in addition to metformin. Measured (m)GFR and effective renal plasma flow (ERPF) were determined by inulin/iohexol and PAH-clearance, respectively, based on timed urine-sampling in fasting and post-protein-rich meal conditions. Intrarenal-hemodynamics were calculated using Gomez-equations; fractional sodium-excretion (FENa) and systemic hemodynamics were evaluated. RESULTS: The meal increased mGFR (+7.3 ± 1.7 mL/min/1.73m2; P < 0.001) and ERPF (+44.3 ± 14.9 mL/min/1.73m2; P = 0.005), with concomitant decrease in renal vascular resistance (RVR; -0.02 ± 0.01 mmHg/L/min; P < 0.001), driven by reduced afferent arteriolar resistance (-1068 ± 241dyne/sec/cm-5; P < 0.001) and lower FENa (-0.21 ± 0.05; P < 0.001). Postprandial mGFR-changes did not correlate with baseline mGFR, but did correlate with postprandial RVR-change (r - 0.57; P < 0.001). After 8 weeks, mGFR tended to decrease with sulfonylurea (P = 0.054) and decreased with empagliflozin (-9.1 ± 3.2 mL/min/1.73m2; P = 0.016), but not with linagliptin. Baseline meal-induced mGFR-changes correlated with 8-week treatment-induced mGFR-changes with empagliflozin (r:0.88; P < 0.001), but not with linagliptin or sulfonylurea. CONCLUSION: Baseline postprandial-RFR predicts GFR-dipping with empagliflozin after 8-weeks, but not with GFR-changes following linagliptin or sulfonylurea. As initial GFR-dipping is associated with long-term kidney benefit, RFR warrants evaluation as a potential additional tool to personalize SGLT2i-therapy.
3. Metabolic surgery mitigates early kidney injury in obese youth with diabetes by suppressing mTORC1/JAK-STAT signaling.
In five youth with T2D undergoing VSG, paired kidney biopsies and multi-omics showed reduced hyperfiltration, kidney volume, mesangial expansion, and microalbuminuria alongside suppression of glycolysis/gluconeogenesis/TCA pathways and activation of AMPK/FOXO3, with decreased mTORC1 (pS6K) and JAK-STAT signaling. Proteomic–transcriptomic integration (Teen-LABS) aligned circulating ligands with intrarenal pathway downregulation, nominating translatable targets.
Impact: Provides first-in-youth, paired renal single-cell and systems-level evidence that bariatric surgery rewires kidney metabolism and inflammation, illuminating druggable nodes (AMPK/FOXO3, mTORC1, JAK-STAT).
Clinical Implications: Reveals mechanistic basis for renoprotection after metabolic surgery in youth with T2D and highlights pathways that could be targeted pharmacologically to mimic surgical benefits.
Key Findings
- Post-VSG reductions in renal hyperfiltration, total kidney volume, mesangial matrix area, and microalbuminuria.
- scRNAseq showed repression of glycolysis, gluconeogenesis, and TCA cycle genes with upregulation of AMPK and FOXO3 in PT and TAL cells.
- Reduced pS6K indicating attenuated mTORC1 activity and decreased JAK-STAT activation in proximal tubule.
- Integration with Teen-LABS proteomics linked lower circulating ligands to diminished intrarenal JAK-STAT signaling.
Methodological Strengths
- Paired pre/post kidney biopsies with single-cell RNA-seq, histology, and volumetry in the same individuals
- Cross-cohort multi-omics integration linking circulating proteomics (Teen-LABS) to renal transcriptomics
Limitations
- Small paired-biopsy sample size (n=5) limits generalizability
- Observational pre/post design without randomized controls cannot fully exclude confounding
Future Directions: Validate findings in larger cohorts, develop noninvasive biomarkers of intrarenal pathway modulation, and test pharmacologic activation of AMPK/FOXO3 or inhibition of mTORC1/JAK-STAT to mimic surgery.
Background Youth with type 2 diabetes (T2D) and severe obesity face high risk of diabetic kidney disease, which metabolic bariatric surgery (MBS) can mitigate. This study explores structural and molecular changes in kidneys after vertical sleeve gastrectomy (VSG), a form of MBS. Methods Paired analyses, including metabolic profiling, kidney volume assessment, histological evaluation, and single-cell RNA sequencing (scRNAseq) on kidney biopsies from five youth with T2D and obesity pre- and 12 months post-VSG in the IMPROVE-T2D (Impact of Metabolic surgery on Pancreatic, Renal and cardiOVascular hEalth in youth with T2D) cohort. Circulating proteomics with kidney transcriptomics, were linked using data from an independent cohort of youth with obesity, with or without T2D, undergoing MBS in Teen-Longitudinal Assessment of Bariatric Surgery (Teen-LABS, n=64). Results Post-VSG, participants lost weight and had improvements in insulin sensitivity and metabolic parameters. Kidney changes included reduced renal hyperfiltration, total kidney volume, mesangial matrix area, and microalbuminuria. scRNAseq in proximal tubule (PT) and thick ascending limb cells indicated repression of glycolysis, gluconeogenesis, and tricarboxylic acid cycle genes, with upregulation of AMP-activated protein kinase (AMPK) and Forkhead box O3 (FOXO3). Decreased metabolic signaling aligned with reduced ribosomal phosphorylated S6K (pS6K), suggesting attenuated mTORC1 activity. JAK-STAT pathway activation in PT was diminished, correlating with lower circulating ligands from Teen-LABS proteomic data. Conclusion MBS/VSG prompts kidney molecular adaptations, providing potential targets for non-surgical interventions against obesity- and diabetes-associated kidney disease.