Background

ObjectiveTo define the variables that predict secondary hyperparathyroidism (HPTH) after duodenal switch (DS) at midterm follow-up (2-3 years). To define the optimal vitamin D (Vit D) level to reduce risk of HPTH after DS. BackgroundHPTH is common following bariatric procedures, especially those with more distal bypasses like the DS. SettingPrivate Practice Tertiary Referral Center

Methods

115 consecutive patients from 12/2020 to 9/2021, who received a DS with a 300 cm alimentary limb and common channel lengths between 100 cm and 150 cm, were analyzed in a retrospective manner. Minimum cholecalciferol (Vit D3) supplementation was 30,000 IU daily. Logistic regression analysis was performed to determine variables predictive of HPTH.

Results

In multivariate analysis, only the preop PTH and Vit D level were statistically significant predictors of HPTH at the last follow-up. 50% of patients with HPTH preop were able to resolve the HPTH postop. Only 15% of patients without HPTH preop developed HPTH at 2-3 years. Vit D levels were higher in patients without HPTH (48 vs 35, p<0.0001). Patients achieving a Vit D level <=40 were 4 times more likely to have HPTH than those with a Vit D level >= 60 for DS (OR=4.04, CI=1.6,10) at follow up of 2-3 years postop.

Conclusions

Higher preop PTH levels indicate an increased risk of developing HPTH after DS. This can be mitigated by achieving higher Vit D levels (i.e >60 ng/ml). Vitamin D supplementation should be adjusted to target Vit D levels for a normal PTH.