Daily Endocrinology Research Analysis
Analyzed 95 papers and selected 3 impactful papers.
Summary
Three standout endocrinology papers emerged today: a mechanistic Diabetes study shows β-hydroxybutyrate improves glucose metabolism in type 1 diabetes by suppressing gut and liver glucose transporters via GPR109A; a Circulation cohort links sugar-sweetened beverages and fruit juice from youth to higher adult hypertension risk; and a JCEM systematic review provides quantitative benchmarks to properly diagnose macroprolactinemia and avoid overtreatment.
Research Themes
- Ketone signaling and glucose transporter regulation in diabetes
- Lifecourse dietary sugars and cardiometabolic risk
- Diagnostic standardization in pituitary disorders (macroprolactinemia)
Selected Articles
1. β-Hydroxybutyrate Improves Glucose Metabolism in Streptozotocin-Induced Type 1 Diabetes by Inhibiting Gut and Liver Glucose Transporters via GPR109A.
Across clinical observations, STZ-T1D mice, and cell models, oral β-hydroxybutyrate improved glucose control and reduced hepatic and intestinal glucose uptake by suppressing SGLT1/GLUT2/GLUT5 via GPR109A, linked to PI3K/AKT/mTOR inhibition. Effects were abrogated by GPR109A blockade or gene silencing, establishing receptor dependence.
Impact: Reveals a receptor-mediated mechanism by which a ketone body directly modulates glucose transport, reframing ketones as active metabolic modulators in T1D rather than mere byproducts.
Clinical Implications: Suggests therapeutic avenues that target GPR109A or controlled nutritional ketosis to reduce intestinal/hepatic glucose flux in insulin-deficient states; translation requires safety evaluation given ketoacidosis risk in T1D.
Key Findings
- Oral 3HB for 7 weeks improved glucose metabolism and alleviated glycogenic hepatopathy in STZ-induced T1D mice.
- FDG-PET/CT showed reduced hepatic and intestinal glucose uptake with 3HB treatment.
- 3HB suppressed SGLT1, GLUT2, and GLUT5 overexpression in liver/intestine; effects reproduced in hepatocytes and IEC-6 cells.
- Mechanism required GPR109A and involved inhibition of the PI3K/AKT/mTOR pathway (validated by antagonist, rapamycin, and siRNA).
Methodological Strengths
- Convergent evidence across clinical observation, in vivo mouse models, and in vitro primary cells.
- Mechanistic dissection using receptor antagonism, siRNA knockdown, and pathway inhibitors plus FDG-PET/CT imaging.
Limitations
- Preclinical study; human interventional data are lacking.
- Potential safety concerns for inducing ketosis in T1D (risk of ketoacidosis) not addressed.
Future Directions: Test GPR109A agonism and controlled ketone therapies in early-phase clinical trials; quantify effects on postprandial glucose and intestinal glucose absorption in humans.
Ketone bodies, particularly β-hydroxybutyrate (3HB), are often elevated in type 1 diabetes (T1D); however, their physiological roles remain unclear. In a low-carbohydrate diet study, patients with insulin-deficient diabetes exhibited reduced fasting blood glucose and increased fasting blood ketone levels, negatively correlated. Another clinical study using continuous glucose and ketone monitoring confirmed inverse glucose-ketone fluctuations. To test causality, we conducted animal and cellular studies. In streptozotocin-induced T1D mice, 7-week oral 3HB administration improved glucose
2. Consumption of Fructose-Containing Food and Beverage Sources in Childhood Through to Adulthood and Risk of Hypertension: A Prospective Cohort Study.
In 25,749 participants followed up to 25 years, sugar-sweetened beverages and fruit juice consumption from youth were independently associated with higher hypertension risk, whereas total fructose intake was not. The analysis adjusted for overall diet quality, physical activity, and other covariates; substitution models were also examined.
Impact: Large lifecourse cohort evidence strengthens guidance to limit SSBs and fruit juice starting in childhood to prevent adult hypertension.
Clinical Implications: Counsel families to limit SSBs and fruit juice and emphasize whole fruit and water from childhood as part of hypertension and cardiometabolic prevention strategies.
Key Findings
- Over up to 25 years, 1,625 of 25,749 participants (6.3%) reported incident hypertension.
- Total fructose intake was not associated with incident hypertension after multivariable adjustment.
- Sugar-sweetened beverages and fruit juice intakes were independently associated with higher hypertension risk despite adjustment for diet quality and physical activity.
- Substitution models assessed replacing SSBs/juice with whole fruit, milk, and water.
Methodological Strengths
- Large, long-term prospective cohort with repeated dietary assessments and robust covariate adjustment.
- Examined source-specific fructose exposures and conducted substitution analyses.
Limitations
- Dietary intake based on self-reported food frequency questionnaires may introduce measurement error.
- Residual confounding and limited generalizability beyond the study population are possible; causality cannot be inferred.
Future Directions: Intervention trials reducing SSB and fruit juice in youth with ambulatory blood pressure and vascular endpoints; policy-level evaluations of school and community beverage environments.
BACKGROUND: High intakes of fructose-containing sugars among children and adolescents is implicated in obesity and related comorbidities, including hypertension. However, sugar-sweetened beverages (SSBs), fruit juices, and whole fruit have different nutritional profiles and matrices, which may confer different effects on blood pressure. METHODS: GUTS (Growing Up Today Study) is a longitudinal cohort of 25 749 individuals (55% female) drawn from 2 enrollment waves, GUTS 1 (n=16 875; baseline 1996) and GUTS II (n=10 918; baseline 2004), followed up prospectively
3. Macroprolactinemia as a diagnostic pitfall in hyperprolactinemia: a systematic review and quantitative synthesis.
Across 45 studies (2,853 macroprolactinemia cases from 21,413 screened), median total prolactin was ~61.4 ng/mL and post-PEG monomeric prolactin ~11.7 ng/mL; extreme total PRL elevations reflected coexisting prolactinomas. Post-PEG monomeric prolactin values, rather than percent PEG recovery alone, best distinguish isolated macroprolactinemia from true hyperprolactinemia.
Impact: Provides quantitative, practice-ready thresholds to interpret prolactin testing, reducing unnecessary imaging and treatment in patients with macroprolactinemia.
Clinical Implications: Use post-PEG monomeric PRL interpretation to identify isolated macroprolactinemia; reserve pituitary imaging and treatment for cases with elevated monomeric PRL or clinical-radiographic concordance.
Key Findings
- Included 45 studies with 2,853 macroprolactinemia cases among 21,413 screened patients.
- Median study-level central total PRL ~61.4 ng/mL (IQR 42.0–80.0); post-PEG monomeric PRL ~11.7 ng/mL (IQR 8.3–13.2).
- Extreme total PRL elevations (median max ~264.5 ng/mL) were attributable to coexisting prolactinomas.
- Post-PEG monomeric prolactin is more informative than %PEG recovery alone to distinguish isolated macroprolactinemia from true hyperprolactinemia.
Methodological Strengths
- PRISMA 2020–guided systematic review with multi-database search and dual independent review.
- Prospective registration (PROSPERO) and quantitative synthesis of assay-specific metrics.
Limitations
- Heterogeneity in confirmation methods (PEG vs GFC), assay platforms, and PEG recovery cutoffs.
- Study-level summaries may not capture within-study variability; publication bias cannot be excluded.
Future Directions: Standardize reporting of post-PEG monomeric PRL across platforms; validate unified interpretive thresholds against GFC and clinical outcomes.
CONTEXT: Macroprolactinemia is a well-recognized cause of hyperprolactinemia and an important diagnostic pitfall in endocrine practice. However, interpretation of published quantitative prolactin data remains sparse as studies vary in confirmation method, assay platform, polyethylene glycol (PEG) recovery cutoff, and reporting of prolactin measurement. EVIDENCE ACQUISITION: PubMed, Embase, Scopus, Web of Science, the Cochrane Library, and Google Scholar were systematically searched. Eligible studies reported macroprolactinemia-specific quantitative prolactin data in patients