Effect of Bariatric Surgery-Induced Weight Loss on Platelet Count and Mean Platelet Volume: a 12-Month Follow-Up Study

Abdominal obesity is strongly correlated with cardiovascular risk and associated with platelet hyperactivity. This hyperactivity is associated with an increase in mean platelet volume (MPV). Few data are available about changes in platelet counts and MPV in obese patients after bariatric surgery (BS). The purpose of this study was to describe quantitative and qualitative changes in the platelet lineage after BS. One hundred twenty-eight consecutive patients were included. The mean age was 43 +/- 12 years, 77 % of patients were female, and the mean preoperative BMI was 44 +/- 6 kg/m(2). Ninety patients (71 %) had a Roux-en-Y gastric bypass (RYGBP), and 38 (29 %) had a sleeve gastrectomy (SG). Patients were evaluated preoperatively, and postoperative follow-up was performed at 3, 6, and 12 months. The postoperative evaluation included blood samples for full blood count (FBC), including measure of mean platelet volume (MPV). At the 12-month follow-up, the reduction in preoperative weight was 29 +/- 9 %. We showed a significant decrease in platelet count (245 +/- 62 vs. 234 +/- 54 G/L; p = 0.0015) found in parallel with a non-significant decrease in MPV (9.27 +/- 1.1 vs. 9.22 +/- 1.05; p = 0.34). With regard to the intervention type, SG caused a more significant decrease in platelet count than RYGBP (p = 0.02). There was no significant difference in MPV variations between the two groups (p = 0.08). Our results suggest that BS has a positive impact on platelet metabolism, possibly mediated by weight loss. These data need to be confirmed to understand the multifactorial benefits of BS on cardiovascular risk in obese patients.