The Pro12Ala polymorphism of PPARγ2 modulates beta cell function and failure to oral glucose-lowering drugs in patients with type 2 diabetes

Maria Masulli; Giuseppe Della Pepa; Sara Cocozza; Mario Capasso; Piero Pignataro; Marilena Vitale; Amalia Gastaldelli; Marco Russo; Pasquale Dolce; Gabriele Riccardi; Angela A Rivellese; Olga Vaccaro

doi:10.1002/dmrr.3392

The Pro12Ala polymorphism of PPARγ2 modulates beta cell function and failure to oral glucose-lowering drugs in patients with type 2 diabetes

Diabetes Metab Res Rev. 2021 Mar;37(3):e3392. doi: 10.1002/dmrr.3392. Epub 2020 Sep 2.

Authors

Affiliations

¹ Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy.
² Department of Molecular Medicine and Medical Biotechnologies, University of Naples Federico II, Naples, Italy.
³ CEINGE Advanced Biotechnologies, Naples, Italy.
⁴ Institute of Clinical Physiology National Research Council, Pisa, Italy.
⁵ Department of Public Health, University of Naples Federico II, Naples, Italy.

^# Contributed equally.

PMID: 32783395
DOI: 10.1002/dmrr.3392

Abstract

Background: We evaluate whether the Pro12Ala polymorphism of peroxisome proliferator-activated receptor γ2 (PPARγ2) has a role in the progression of diabetes by modulating the occurrence of treatment failure to glucose-lowering drugs.

Methods: We studied 215 patients with type 2 diabetes participating in the Thiazolidinediones Or Sulphonylureas and Cardiovascular Accidents Intervention Trial study. All participants were insufficiently controlled (glycated haemoglobin [HbA_1c ] 7.0%-9.0%) with metformin 2 g/day and were randomly allocated to add-on pioglitazone or a sulfonylurea. Treatment failure was defined as HbA_1c ≥8% on two consecutive visits, 3 months apart.

Results: Carriers or non-carriers of the polymorphism had similar age, body mass index, and diabetes duration. Ala carriers had lower fasting plasma insulin, better insulin sensitivity (Homeostasis Model Assessment [HOMA]2-%S), and worse beta cell secretion (HOMA2-%B) than non-carriers. During 24 months of follow-up, 32.5% among the Ala carriers and 8.6% among non-carriers (P < 0.001) developed treatment failure with a cumulative incidence of 18.6 vs 4.6/100 person-years. Those patients who developed treatment failure were older, had a younger age at diabetes diagnosis (48 ± 10 vs 52 ± 7 years; P = 0.032), higher HbA_1c (8.1 ± 0.5 vs 7.7 ± 0.5%; P < 0.001), and lower HOMA2-%B (30 ± 12 vs 46 ± 29; P = 0.015) at study entry, as compared to those who did not develop treatment failure. At multivariate analysis, the Pro12Ala polymorphism was significantly associated with treatment failure (hazard ratio [HR] 4.45; 95% confidence interval [CI] 1.79-11.1; P < 0.001); HbA_1c at study entry was the other independent predictor of failure in this study population.

Conclusion: The Pro12Ala polymorphism is associated with a greater insulin sensitivity, reduced beta cell function and a substantially increased risk of treatment failure.

Trial registration: ClinicalTrials.gov NCT00700856.

Keywords: PPARγ2; beta cell function; insulin sensitivity; pioglitazone; treatment failure; type 2 diabetes.

Publication types

Clinical Study
Research Support, Non-U.S. Gov't

MeSH terms

Administration, Oral
Diabetes Mellitus, Type 2* / drug therapy
Diabetes Mellitus, Type 2* / genetics
Humans
Hypoglycemic Agents / administration & dosage
Insulin-Secreting Cells / physiology
PPAR gamma* / genetics
Polymorphism, Genetic
Treatment Failure

Substances

Hypoglycemic Agents
PPAR gamma

Associated data

ClinicalTrials.gov/NCT00700856