The American Diabetes Association 72nd Scientific Sessions:
Antidepressant Medications Can Increase C-reactive Protein Levels
It’s known that antidepressant medications (ADM) are associated with type 2 diabetes, but it’s no understood which mechanism(s) are responsible for this. Research presented at the 72nd Scientific Sessions of the American Diabetes Association explored this link.
The poster was “Antidepressant Medication use Predicts Elevate C-Reactive Protein Levels in the Diabetes Prevention Program.” As the title notes, this was part of the Diabetes Prevention Program (DPP).
The DPP Research Group looked at if the shared inflammatory markers that are associated with type 2 diabetes and depression: could those markers be a mediator between antidepressants and diabetes?
To explore this question, the researchers used the following data in the DPP:
- ADM and depression symptom scores (Beck Depression Inventory [BDI])
- Serum inflammatory markers (C-reactive protein [CRP] and interleukin-6 [IL-6])
These were assessed at baseline and at 1 year in all groups of the DPP—metformin intervention (MET), lifestyle intervention (ILS), and placebo (PLB). In those groups, type 2 diabetes was diagnosed semi-annually.
At baseline, the 3,006 DPP participants had a mean BMI of 34 kg/m2 (standard deviation [SD] 6). The mean age was 50.8 (SD 10.6 years), and 68% were female.
In the group, 167 were using antidepressant medications; 68% of those were using SSRIs.
On the BDI, 327 (10.3%) had scores ≥ 11 (mean BDI 4.5 ± 4.5).
The inflammatory markers were looked at for each group of the DPP. For CRP, the following levels were seen:
- MET: .58 ± .73 mg/dL
- ILS: .58 ± .65 mg/dL
- PLB: .61 ± .77 mg/dL
For IL-6, the following levels were seen:
- MET: 2.4 ± 2.2 pg/mL
- ILS: 2.5 ± 2.2 pg/mL
- PLB: 2.5 ± 2.0 pg/mL
Baseline Multiple Regression Analyses
Using multiple regression analyses, the researchers looked at the cross-sectional and longitudinal relationship between ADM, BDI, CRP, and IL-6. BDI was the continuous variable. At baseline, it was seen that ADM was associated directly with CRP (controlling for demographic, anthropometric, treatment group, and other medications) (ratio of adjusted means = 1.16 (95% confidence interval [CI]: 1.01-1.34).
This association was not seen with BDI.
1-year Multiple Regression Analyses
When controlling for the same variables at 1-year, the baseline ADM predicted a higher CRP (ratio of adjusted means = 1.25 (95% CI: 1.07-1.45). This was not true of baseline BDI at 1-year.
ILS and MET, compared to PLB, predicted a lower CRP, but no relationship between ADM or BDI was seen with IL-6.
The development of type 2 diabetes was not predicted by baseline CRP or IL-6 inflammatory markers, nor did those markers mediate the relationship between antidepressant medications and type 2 diabetes.
Antidepressant Medication and Inflammatory Markers Conclusion
This study concludes that while there is “new evidence that ADM significantly predicts higher CRP in persons at risk for type 2 diabetes,” it cannot be said that inflammatory markers mediate the relationship between antidepressants and type 2 diabetes.