Pharmacological TreatmentsPrediabetesRisk Factors
Research Summary
Analyzed using Evidence Intelligence™

Pioglitazone may reduce body fat inflammation in insulin resistance

Last updated May 6, 2026

Key finding

In insulin-resistant adults with impaired glucose tolerance, pioglitazone was linked to fewer inflammatory cells in adipose tissue, better capillary density, higher elastin content, and improved insulin sensitivity.

This study re-examined fat tissue from insulin-resistant adults before and after pioglitazone treatment. Pioglitazone was linked to fewer adipose macrophages and mast cells, more capillaries, higher elastin content, and better insulin sensitivity. Because the treatment group was small and the analysis was based on secondary tissue studies, the findings are promising but not definitive.

Quick read

Study at a glance

The essential study design details in one scan.

EvidenceScore™

Low

Study type

non-randomized clinical trial (non-RCT or NRCT)

Follow-up

Medium-Term (3–12 mo)

Risk of bias

Some Concerns

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Plain-language summary

What this paper says

A plain-language read of the study’s main message and where it applies.

Study focus

In insulin-resistant adults with impaired glucose tolerance, pioglitazone was linked to fewer inflammatory cells in adipose tissue, better capillary density, higher elastin content, and improved insulin sensitivity.

Published in

Journal Reference

Publication details and source links for this paper.

Spencer M, Yang L, Adu A, et al. Pioglitazone Treatment Reduces Adipose Tissue Inflammation through Reduction of Mast Cell and Macrophage Number and by Improving Vascularity. PLoS One. 2014;9(7):e102190. doi:10.1371/journal.pone.0102190

Main Effects

Adipose tissue macrophage count ↓ after pioglitazone

Adipose tissue mast cell count ↓ after pioglitazone

Capillary density ↑ and elastin content ↑ in adipose tissue

Insulin sensitivity ↑ after treatment

Evidence network

How this study fits

Understand where this research contributes within the broader evidence network.

Evidence Context

This study contributes evidence to Pioglitazone and Adipose tissue elastin content, Adipose tissue macrophage count, Adipose tissue mast cell count, and 2 more.

Primary intervention

Pioglitazone

Primary outcomes

  • Adipose tissue elastin content
  • Adipose tissue macrophage count
  • Adipose tissue mast cell count

Evidence relationships

Intervention and outcome relationships this study adds to the evidence network.

5
Evidence pairs
5
Relationships
1
Evidence topics
contributes_evidence

Editorial context

Why this study matters

See why this paper is useful beyond its individual results.

Evidence network role

This section describes how the study fits into the current evidence network. It does not determine whether an intervention works on its own.

Moderate contributionModerate confidenceNetwork score: 46

1

Related topics

5

Evidence pairs

143

Related studies

High relevance in at least one topic

Why it is useful

  • Contributes to 5 evidence relationships
  • Uses a randomized study design signal
  • Linked to 1 direct semantic evidence topic

Topic contributions

Evidence topic

Contributes evidence

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Primary evidence

Evidence relationship

Thiazolidinediones and Adipokine and Angiogenic Markers

Related evidence

Evidence relationship

Thiazolidinediones and Endothelial Function

Save evidence

Evidence relationship

Thiazolidinediones and Insulin Resistance

Save evidence

Core evidence

Study findings

The primary outcomes reported in this study.

Adipose tissue elastin content

Pioglitazone → Adipose tissue elastin content

Pioglitazone → Adipose tissue elastin content

Evidence Intelligence™
EvidenceScore™
58
Emerging
ImpactScore™
100
Very Positive
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Add to Evidence Tracker

Adipose tissue macrophage count

Pioglitazone → Adipose tissue macrophage count

Pioglitazone → Adipose tissue macrophage count

Evidence Intelligence™
EvidenceScore™
58
Emerging
ImpactScore™
100
Very Positive
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Add to Evidence Tracker

Adipose tissue mast cell count

Pioglitazone → Adipose tissue mast cell count

Pioglitazone → Adipose tissue mast cell count

Evidence Intelligence™
EvidenceScore™
58
Emerging
ImpactScore™
100
Very Positive
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Add to Evidence Tracker

Capillary density

Pioglitazone → Capillary density

Pioglitazone → Capillary density

Evidence Intelligence™
EvidenceScore™
58
Emerging
ImpactScore™
100
Very Positive
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Add to Evidence Tracker

Insulin sensitivity

Pioglitazone → Insulin sensitivity

Pioglitazone → Insulin sensitivity

Evidence Intelligence™
EvidenceScore™
58
Emerging
ImpactScore™
100
Very Positive
ConsistencyScore™
unclear
Not enough independent studies
Supporting studies: Based on 1 study
Add to Evidence Tracker

Evidence Library

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evidence suggest

Evidence Suggest

  • Pioglitazone lowered total adipose macrophages and reduced pro-inflammatory M1 macrophages.
  • Mast cell density fell from 24 to 13 cells per mm2 after pioglitazone treatment.
  • Capillary density and adipose elastin content increased, suggesting improved tissue structure and blood supply.
  • Insulin sensitivity improved in the treated participants in the paired pre-post analysis.
who this applies

Who this applies to

These findings apply most directly to obese, insulin-resistant adults with impaired glucose tolerance who are at high risk for type 2 diabetes. The results are especially relevant to people being studied for early metabolic dysfunction rather than established treated diabetes.

keep in mind

Keep in Mind

The improvements were seen mainly in adipose tissue biology and insulin sensitivity, not in a large clinical outcomes trial. The treatment group was small, and this paper re-used participants from previous intervention studies. That means the study helps explain how pioglitazone may work, but it does not by itself prove broad clinical benefit for all high-risk patients.

between the lines

Between the Lines

  • Only nine participants were included in the pioglitazone tissue analysis.
  • This was a secondary mechanistic analysis based on prior intervention cohorts.
  • There was no dedicated parallel placebo group for the pioglitazone biopsy analysis.
  • Most outcomes were tissue and biomarker measures rather than patient-centered clinical outcomes.

Evidence Library

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Connected Evidence

Explore related studies, evidence collections, and research questions.

Relationships organized using the Dediabetes Evidence Intelligence™ framework.

This study contributes to evidence on Thiazolidinediones and Adipokine and Angiogenic Markers, Thiazolidinediones and Adipokine and Angiogenic Markers.

Related evidence relationships

Explore in Evidence Explorer

This study contributes to the evidence on the following intervention-outcome relationships.

Questions answered by this study

Generated from the study's connected evidence using Evidence Intelligence™.

Does Thiazolidinediones improve adipokine and angiogenic markers?

Moderate Evidence

Thiazolidinediones appears to improve Adipokine and Angiogenic Markers.

ConsistencyScore™: Results are consistent across studies.

Ranked evidence signals

  1. 1

    Adipose tissue elastin content

    EvidenceScore™ Emerging | EvidenceScore™ 58.5 | strong positive | ConsistencyScore™ Unclear | 1 study

  2. 2

    Adipose tissue macrophage count

    EvidenceScore™ Emerging | EvidenceScore™ 58.5 | strong positive | ConsistencyScore™ Unclear | 1 study

  3. 3

    Adipose tissue mast cell count

    EvidenceScore™ Emerging | EvidenceScore™ 58.5 | strong positive | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a small number of supporting studies and should be interpreted cautiously.

Limitations

  • Only a small number of supporting studies are available.
  • Population details are unavailable.
2 supporting studiesUpdated: Jul 2026

Does Thiazolidinediones improve insulin resistance?

Emerging Evidence

Thiazolidinediones appears to improve Insulin Resistance.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Insulin sensitivity

    EvidenceScore™ Emerging | EvidenceScore™ 58.5 | strong positive | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026

Does Thiazolidinediones improve endothelial function?

Emerging Evidence

Thiazolidinediones appears to improve Endothelial Function.

ConsistencyScore™: Consistency cannot yet be determined from the available evidence.

Ranked evidence signals

  1. 1

    Capillary density

    EvidenceScore™ Emerging | EvidenceScore™ 58.5 | strong positive | ConsistencyScore™ Unclear | 1 study

Why this answer: This answer is based on a single supporting study.

Limitations

  • Only one supporting study is available.
  • Consistency cannot yet be determined.
  • Population details are unavailable.
1 supporting studyUpdated: Jul 2026
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