Incidence of diabetes mellitus among people living with and without HIV in British Columbia, Canada between 2001 and 2013: a longitudinal population-based cohort study

Abstract

Introduction: People living with HIV (PLHIV) are increasingly at risk of age-related comorbidities such as diabetes mellitus (DM). While DM is associated with elevated mortality and morbidity, understanding of DM among PLHIV is limited. We assessed the incidence of DM among people living with and without HIV in British Columbia (BC), Canada, during 2001-2013.

Methods: We used longitudinal data from a population-based cohort study linking clinical data and administrative health data. We included PLHIV who were antiretroviral therapy (ART) naïve at baseline, and 1:5 age-sex-matched persons without HIV. All participants had ≥5 years of historic data pre-baseline and ≥1 year(s) of follow-up. DM was identified using the BC Ministry of Health's definitions applied to hospitalisation, physician billing and drug dispensation datasets. Incident DM was identified using a 5-year run-in period. In addition to unadjusted incidence rates (IRs), we estimated adjusted incidence rate ratios (IRR) using Poisson regression and assessed annual trends in DM IRs per 1000 person years (PYs) between 2001 and 2013.

Results: A total of 129 PLHIV and 636 individuals without HIV developed DM over 17 529 PYs and 88,672 PYs, respectively. The unadjusted IRs of DM per 1000 PYs were 7.4 (95% CI 6.2 to 8.8) among PLHIV and 7.2 (95% CI 6.6 to 7.8) for individuals without HIV. After adjustment for confounding, HIV serostatus was not associated with DM incidence (adjusted IRR: 1.03, 95% CI 0.83 to 1.27). DM incidence did not increase over time among PLHIV (Kendall trend test: p=0.9369), but it increased among persons without HIV between 2001 and 2013 (p=0.0136).

Conclusions: After adjustment, HIV serostatus was not associated with incidence of DM, between 2001 and 2013. Future studies should investigate the impact of ART on mitigating the potential risk of DM among PLHIV.

Keywords: HIV & AIDS; diabetes & endocrinology; epidemiology.

Figure 1

Flowchart outlining derivation of the two final comparison analytical samples of 2972 people living with HIV (PLHIV) and an age-sex-matched 13 869 HIV-negative individuals in British Columba, Canada between 2001 and 2013. *HIV-negative individuals were eligible for matching if matched at least one individuals from the final HIV-positive sample, where (1) sex was an exact match; (2) birth year was an exact match; (3) baseline date was older than or equal to PLHIV baseline date; (4) earliest contact date (ie, earliest of hospital admission date, Medical Services Plan (MSP) service date, PharmaNet service date or MSP registration date) was ≥5 years earlier than PLHIV baseline date and (5) end of follow-up date was ≥1 year later than the PLHIV baseline date.Abbreviations: ART, antiretroviral therapy; BC, British Columbia; COAST: the Comparative Outcomes and Service Utilization Trends Study; DTP: Drug Treatment Programme; DM: diabetes mellitus.

Figure 2

Annual trends in unadjusted incidence rates of diabetes mellitus in British Columbia, Canada, during 2001–2012 (by fiscal year). Note: fiscal years in this study start from 1 April to 31 March. For example, the year 2001 in the figure refers to the year between 1 April 2001 and 31 March 2002; and year 2012 refers to 1 April 2012–31 March 2013.Abbreviations: PYs, person years; PLHIV, people living with HIV.