Shingles may signal hidden diabetes

Older adults with shingles had a higher 1-year rate of newly diagnosed Type 2 diabetes.
*Retrospective matched cohort study; Level 2b (OCEBM).

Citation

Lai SW, Liao KF. Herpes zoster as a potential clinical marker of undiagnosed Type 2 diabetes in older adults: a retrospective cohort study. Family Practice. 2026;43:1-6. doi:10.1093/fampra/cmag043

Background

Diabetes is a known risk factor for shingles, but whether shingles can help identify previously unrecognized diabetes is less clear. This study tested whether older adults with shingles were more likely to receive a new Type 2 diabetes diagnosis soon afterward.

Patients

Adults aged 65–84 years in 40 Asia-Pacific health organizations in the TriNetX electronic health record network. Patients with prior diabetes diagnosis or diabetic-range fasting glucose or hemoglobin A1c before the index date were excluded; 1 year of follow-up was required.

Intervention

Diagnosis of shingles.

Control

Age- and propensity-matched adults without shingles.

Outcome

Newly diagnosed Type 2 diabetes.

Follow-up Period

Primary: 1 year; sensitivity analyses: 3 and 6 months.

Results

Time window Shingles group Control group Association Absolute increase
1 year (primary) 382/16,175; 2.36% 56/16,336; 0.34% Hazard ratio 6.52; 95% confidence interval 4.92–8.63 2.02%; number needed to harm ≈50
3 months 1.13% 0.21% Hazard ratio 5.26; 95% confidence interval 3.65–7.59 0.92%
6 months 1.65% 0.26% Hazard ratio 6.13; 95% confidence interval 4.43–8.49 1.39%

The analysis used matched observational cohorts. Results suggest association, not causation.

Limitations

Diagnosis codes may misclassify shingles or diabetes. People with shingles may have had more visits and testing, increasing diabetes detection. Important diabetes risks such as family history, body weight, diet, and activity were incompletely measured. Results may not generalize beyond Asia-Pacific settings. Despite exclusions, some patients may already have had unrecognized diabetes.

Funding

No funding; no stated industry bias concern.

Clinical Application

Consider checking glucose or hemoglobin A1c in older adults with shingles, especially if screening is overdue or diabetes risk factors are present.