Preoperative Vitamin D Deficiency is a Risk Factor for Postthyroidectomy Hypoparathyroidism: A Systematic Review and Meta-Analysis of Observational Studies

Abstract

Context Whether pre-operative vitamin D deficiency (VDD) contributes to post-operative hypoparathyroidism (hypoPT) risk is unknown. Objective To meta-analyze the best available evidence regarding the association between pre-operative vitamin D status and hypoPT risk. Data Sources: A comprehensive literature search was conducted in PubMed, CENTRAL and Scopus databases, up to October 31, 2020. Study Selection Patients undergoing thyroidectomy with pre-operative vitamin D status and post-operative hypoPT data. Data Extraction Two researchers independently extracted data from eligible studies. Data synthesis Data were expressed as risk ratio (RR) with 95% confidence interval (CI). The I 2 index was employed for heterogeneity. Results Thirty-nine studies were included in the quantitative analysis (61,915 cases with transient and 5,712 with permanent hypoPT). Patients with VDD demonstrated a higher risk for transient hypoPT compared with those with pre-operative vitamin D sufficiency (RR 1.92, 95% CI 1.50-2.45, I 2 85%). These results remained significant for patients with pre-operative 25(OH)D concentrations ≤20 ng/ml (mild VDD; RR 1.46, 95% CI 1.10-1.94, I 2 88%) and ≤10 ng/ml (severe VDD; RR 1.98, 95% CI 1.42-2.76, I 2 85%). The risk of permanent hypoPT was increased only in cases with severe VDD (RR 2.45, 95% CI 1.30-4.63, I 2 45%). No difference was evident in subgroup analysis according to study design or quality. Conclusions Patients with pre-operative VDD are at increased risk of transient hypoPT following thyroidectomy. The risk for permanent hypoPT is increased only for those with severe VDD.

Vitamin D Insufficiency Predicts Susceptibility of Parathyroid Hormone Reduction after Total Thyroidectomy in Thyroid Cancer Patients

“…Several studies reported that low preoperative 25OHD was associated with postoperative hypoparathyroidism or hypocalcemia [11,[21][22][23]. Bove et al [11] analyzed clinical and lab data of 177 patients who underwent total thyroidectomy and found preoperative vitamin D deficiency (<25 ng/mL) was an independent risk factor in the development of hypocalcemia [24]. In contrast to the abovementioned studies, some studies found no significant association between preoperative 25OHD and postoperative hypoparathyroidism [9,[25][26][27].…”

“…Bove et al [ 11 ] analyzed clinical and lab data of 177 patients who underwent total thyroidectomy and found preoperative vitamin D deficiency (<25 ng/mL) was an independent risk factor in the development of hypocalcemia (OR: 14.8, 95% CI: 1.59–59.70, p = 0.012). Recently, a meta-analysis was published by Vaitsi et al [ 24 ] which included 39 observational studies of patients undergoing thyroidectomy with preoperative vitamin D status and postoperative hypoparathyroidism data. Patients with preoperative vitamin D deficiency demonstrated a higher risk for transient hypoparathyroidism compared with those with preoperative vitamin D sufficiency (RR: 1.92, 95% CI: 1.50–2.45, I 2 = 85%) [ 24 ].…”

“…Recently, a meta-analysis was published by Vaitsi et al [ 24 ] which included 39 observational studies of patients undergoing thyroidectomy with preoperative vitamin D status and postoperative hypoparathyroidism data. Patients with preoperative vitamin D deficiency demonstrated a higher risk for transient hypoparathyroidism compared with those with preoperative vitamin D sufficiency (RR: 1.92, 95% CI: 1.50–2.45, I 2 = 85%) [ 24 ].…”

Does preoperative vitamin D deficiency delay recovery time from transient hypocalcemia after thyroidectomy?

“…In contrast, in their study with 30 patients (12 with vitamin D deficiency and 18 with normal vitamin D levels), Alkhalili et al (22) reported that preoperative vitamin D deficiency was associated with postoperative hypocalcemia. In a systematic review and meta-analysis of observational study, Konstantina et al reported that patients with preoperative vitamin D deficiency had an increased risk of transient hypoparathyroidism following thyroidectomy, while those with severe vitamin D deficiency had an increased risk of permanent hypoparathyroidism (28).…”

How Long Does It Take to Regain Normocalcaemia in the Event of Postsurgical Hypoparathyroidism? A Detailed Time Course Analysis

“…Because this is a representation of a real-world cohort, data regarding preoperative calcium levels, corrected or ionized calcium values, preoperative medication, or preoperative vitamin D levels were not consistent enough to allow for proper evaluation. This might have been worthwhile, since preoperative vitamin D deficiency has been identified as a possible risk factor of PH [ 28 ]. Moreover, as a result of the inclusion criteria of the present study, there is a lack of data from “controls”, so no conclusion can be drawn with regard to the association of postoperative PTH levels with the incidence of PH.…”