SGLT2 inhibitors show no excess pneumonia or sepsis compared with DPP-4 inhibitors

Design

Systematic review and active-comparator meta-analysis of observational cohorts

Population

Adults with type 2 diabetes in 18 cohorts (11 pooled)

Primary outcome

Incident pneumonia and sepsis, SGLT2 inhibitor vs DPP-4 inhibitor

Effect

Pneumonia ratio 0.65 (95% CI 0.55–0.75); sepsis 0.65 (0.53–0.80), prediction interval 0.38–1.13; very low certainty

A meta-analysis of real-world cohorts compared severe infections in adults with type 2 diabetes starting an SGLT2 inhibitor or a DPP-4 inhibitor. Eighteen cohorts were included, and 11, all at moderate risk of bias, contributed to the pooled estimates.

For pneumonia (five studies) the pooled ratio was 0.65 (95% CI 0.55–0.75), with heavy heterogeneity (I² about 90%). Removing one cohort with delayed follow-up gave 0.61 (0.56–0.67) with no heterogeneity. For sepsis the exploratory ratio was also 0.65, but the prediction interval crossed 1 (0.38–1.13).

The authors are clear that these lower numbers should not be read as protection: certainty was very low and the comparison is observational. What the data do support is reassurance — there is no signal that SGLT2 inhibitors raise the average risk of serious infection.

This matters for older or frail patients, where prescribers sometimes hold back an SGLT2 inhibitor over infection worries. Genital mycotic infection remains a real and separate effect.

• Severe infection risk is not a reason to avoid an SGLT2 inhibitor in favour of a DPP-4 inhibitor
• Keep counselling on genital hygiene and mycotic infection — that risk is separate and real
• Pause an SGLT2 inhibitor during an acute illness with poor intake, as sick-day rules advise
• Do not tell patients the drug prevents pneumonia; the data are observational and very low certainty

Why it matters

It removes one of the quieter reasons older patients are kept on a DPP-4 inhibitor instead.

Don't overread it

The lower pooled ratios are observational and very low certainty; they do not show a preventive effect.

The statistics, in plain English

A ratio of 0.65 would mean about a third fewer events, but I² near 90% says the studies disagreed a lot. The prediction interval for sepsis, 0.38 to 1.13, is the range the next study's result could fall in — because it includes 1, a new study might find no difference at all.

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