Background: While the use of opioids for chronic non-cancer pain (CNCP) has increased
dramatically in the past 2 decades, concern exists about the safety of opioids, particularly
with the extensive use among individuals with CNCP.
Objective: To assess the risk of type 2 diabetes (T2D) among adults exposed to opioids
for non-cancer pain.
Study Design: Nested case-control study.
Setting: United Kingdom-based General Practice Research Database (GPRD).
Methods: Among 1.7 million opioid users with at least one prescription for an opioid to
treat non-cancer pain in the GPRD (1990 – 2008), we identified all incident T2D cases with
at least 2 years of medical history before their first diagnosis (index date). For each case
we randomly selected up to 2 controls matched on age, gender, index date, and general
practice. The same eligibility requirements were applied to controls as to cases. We defined
“any exposure” as at least 2 prescriptions for an opioid within 2 years before the index date
and defined “nonuse” as no use or only one prescription within 2 years (reference). For
any exposure to opioids we further evaluated timing of use, cumulative use, and individual
opioid type. Conditional logistic regression was used to estimate adjusted odds ratios
(AORs) and 95% confidence intervals (CIs) controlling for confounders.
Results: We identified 50,468 T2D cases to which we matched 100,415 controls. Cases
were more likely than controls to be former smokers, heavier, and to have more comorbidities, co-medications, and visits to their general practitioners. After adjusting for
important confounders there was no increased risk for T2D among those exposed to any
opioid compared to nonusers (AOR = 1.03, 95% CI 1.00 – 1.06). The results did not change
when we evaluated timing of use, cumulative use, or individual opioid type.
Limitations: Misclassification of exposure may have occurred; limited data for some
individual opioid types.
Conclusion: This study found no association between use of opioids and risk of T2D
among non-cancer adults.
Key words: Opioids, type 2 diabetes, non-cancer pain, General Practice Research Database
GPRD, nested case-control, safety, adults