Hydrogenology
Hydrogenology editorial study record

Efficacy and safety of hydrogen inhalation therapy in type 2 diabetes mellitus patients inadequately controlled by metformin alone

Lin G, Ni T. · Adv Clin Med. 2022;12(10):9605–9612.

HumanInhaled H₂Published 2022
Study record, not medical adviceThis page reports one source and Hydrogenology’s source-text extraction. It does not establish that molecular hydrogen is effective, safe or appropriate for any person. Human, animal and laboratory evidence must not be treated as equivalent.
Source and classification

What kind of evidence is this?

Evidence stream

Human

Reported design

Randomized controlled parallel study

Research topic

Metabolic and lipid health

Administration classification

Inhaled H₂

Study result signal

Reported positive between-group signal with high uncertainty.

Outcome type

Metabolic laboratory outcomes, weight and reported adverse events.

Reported in the source

Methods at a glance

Population or model

Adults with type 2 diabetes inadequately controlled by metformin.

Sample

110 participants; 55 per group.

Duration

12 weeks.

Intervention

Metformin plus H₂ inhalation for three hours daily.

Hydrogen form

Inhaled H₂-containing gas.

H₂ specification

Generator output 3,000 mL/hour; the inhaled H₂ concentration was not reported.

H₂ flow

3,000 mL/hour generator output; delivered concentration unclear.

O₂ delivered with H₂

No oxygen co-delivery was reported.

Comparator

Metformin plus placebo gas.

Reported, not endorsed

Outcomes and reported result

Outcomes measured

HbA1c, glucose profile, lipids, HOMA indices, weight and adverse events.

Reported result

The article reports favorable between-group differences for multiple metabolic measures and fewer adverse events in the H₂ group.

Results-extraction completeness

The full article methods, intervention, outcomes, positive and null findings, funding and conflict statements were checked.

A reported association, difference or mechanism is not automatically a clinical benefit. Null findings, outcome type, study design and precision all matter.

Interpretation limits

Cautions and applicability

Design and reporting cautions

Single-center report with unclear allocation concealment and blinding, many outcomes and no reported inhaled H₂ concentration.

Applies directly to

The reported metformin-treated population only.

Preliminary appraisal framework

Cochrane RoB 2 — preliminary

Preliminary risk-of-bias status

High risk

Appraisal rationale

Randomization was stated, but sequence generation, concealment, blinding and protocol-based outcome selection were not established.

Appraisal domains

Random sequence reported or described · Allocation concealment not fully established · Deviations and co-interventions checked · Outcome measurement checked by endpoint · No outcome-level protocol comparison completed

No single-study GRADE certainty rating is assigned. Certainty is assessed by important outcome across a complete eligible evidence set, not by attaching a final grade to one source.

Provenance

Sources and record status

Identifiers

DOI: 10.12677/acm.2022.12101389 · DOI: 10.12677/acm.2022.12101389

Publisher access

A free publisher or repository full article was checked.

Extraction basis

Publisher or repository full article and bibliographic record; checked 10 August 2026.

Record revision

2026-08-10