Risk of Herpes Zoster in Patients with Diabetes

A systematic review found patients with diabetes were associated with a 38% increased risk of developing herpes zoster. 

Herpes zoster, or shingles, is a self-limiting condition caused by the reactivation of the latent varicella-zoster virus, mainly in patients with a weak immune system. Even though shingles is often self-limiting, multiple complications can affect the quality of life of many patients. Post-herpetic neuralgia is the most distressing complication of shingles due to persistent pain symptoms. Diabetes is a known risk factor for macrovascular and microvascular complications; in addition, patients with diabetes are also more susceptible to infections. Knapp and Kosuke et al. showed that diabetes is also a risk factor for herpes zoster and post-herpetic neuralgia. However, there was a lack of inclusive evidence in the diabetes population from previous meta-analyses.   

The study in this discussion is a meta-analysis of previously published studies with the primary outcome of evaluating the relationship between herpes zoster and diabetes; to hopefully identify the subgroups that might benefit from early vaccination, the secondary outcome was to identify additional risk factors in patients with diabetes. The study included four case-control studies and 12 cohort studies that met the inclusion criteria, included participants age 18 or older, investigated the incidence, risk, or consequences of herpes zoster among patients with and without type 1 or type 2 diabetes.   

In the primary objective, patients with diabetes were associated with a 38% increased risk of developing herpes zoster (95% CI 1.21 to 1.57, high heterogeneity). Patients with diabetes in both age groups, younger than and older than 50 years, had a higher risk of developing herpes zoster (pooled RR 1.41, 95% CI 1.20 to 1.65 and pooled RR 1.49, 95% CI 1.10 to 2.02, respectively). Patients with type 1 diabetes had a significant association with increased risk for herpes zoster (pooled RR 1.59, 95% CI 1.01 to 2.50), while patients with type 2 diabetes had a non-significant association with increased risk  (pooled RR 1.48, 95% CI 0.96 to 2.29). Other factors such as duration of diabetes and insulin-dependent status did not show any statistical difference between subgroups. HbA1c levels of above or below 8% did not have a statistical difference in risk, except for patients younger than 45 years with an HbA1c greater than 8% who had a significantly higher risk. Patients with diabetes and cardiovascular disease or chronic kidney disease had a higher risk  than those who did not (cardiovascular disease: pooled RR 1.16, 95% CI 1.06 to 1.26; chronic kidney disease: pooled RR 1.09, 95% CI 0.9 to 1.16).  

The authors concluded that individuals with diabetes have an increased risk of herpes zoster compared to the general population. Even though this study showed that type 2 diabetes did not significantly increase the risk, the data came from only two studies; most of the other studies did not separate the type of diabetes. More data from a more extensive study may be necessary to confirm the association. On the other hand, patients with cardiovascular diseases often have other risk factors for the development of herpes zoster, such as hypertension and hyperlipidemia. This study suggested that the risk for herpes zoster is high even for patients with diabetes who are under 50 years old. More comprehensive studies are needed to confirm further and thus to review the benefit of administering the varicella vaccine to younger patients.  

Practice Pearls: 

• Patients with diabetes are at higher risk for developing herpes zoster than patients without diabetes. 
• Patients with diabetes are at risk for cardiovascular and chronic kidney diseases, which are additional risk factors for herpes zoster. 
• Shingrix is the most prominent vaccine for adults 50 years and older to prevent herpes zoster. 

Huang, Chun-Ta et al. “Association between Diabetes Mellitus and the Risk of Herpes Zoster: A Systematic Review and Meta-analysis.” The Journal of clinical endocrinology and metabolism. 18 Sep. 2021,  

Knapp, Sylvia. “Diabetes and infection: is there a link?–A mini-review.” Gerontology vol. 59,2 (2013): 99-104.  

Kawai, Kosuke, and Barbara P Yawn. “Risk Factors for Herpes Zoster: A Systematic Review and Meta-analysis.” Mayo Clinic proceedings vol. 92,12 (2017): 1806-1821.  

Ding Nguyen, PharmD Candidate, University of South Florida Taneja College of Pharmacy