High prevalence of peripheral neuropathy in multiple myeloma patients and the impact of vitamin D levels, a cross-sectional study

Abstract

Purpose Peripheral neuropathy (PN) is common in patients with multiple myeloma (MM). We hypothesized that the relationship between hypovitaminosis D and PN described in diabetes mellitus patients may also be present in MM patients. Methods To study this potential association, we assessed the incidence of hypovitaminosis D (vitamin D < 75 nmol/L [= 30 ng/mL]) in smouldering and active MM patients in two Dutch hospitals. Furthermore, a validated questionnaire was used to distinguish different PN grades. Results Of the 120 patients included between January 2017 and August 2018, 84% had an inadequate vitamin D level (median vitamin D level 49.5 nmol/L [IQR 34–65 nmol/L]; mean age: 68 years [SD ± 7.7]; males: 58%). PN was reported by 69% of patients (n = 83); however, of these 83 patients, PN was not documented in the medical records of 52%. An association was found between lower vitamin D levels and higher incidence of PN in the total population (P = 0.035), and in the active MM patients (P = 0.016). Conclusion This multi-centre cohort study showed that PN and hypovitaminosis D are common in MM patients, and addressing low vitamin D levels in the treatment of MM patients might be beneficial in reducing the risk of PN. More attention for PN is warranted, as PN is underreported by clinicians. Further research is needed to fully understand the implications of vitamin D in the development of PN in patients with MM. Clinical trial registration Netherland Trial Register NL5835, date of registration July 28, 2016

Vitamin D and Multiple Myeloma: A Scoping Review

“…Records from all three deduped databases were then amalgamated in Zotero and underwent inter-database deduplication, removing 207 studies, leaving 1264 which were subsequently uploaded to Rayyan for screening. Abstract and title screening (blinded) performed independently by two investigators (NM and AP) excluded 1214 records, leaving 50 to screen by full text, of which 35 were subsequently excluded, yielding 15 publications [ 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 ] for this scoping review. One study produced two publications reporting on different outcomes [ 21 , 22 ]; hence 14 separate studies were identified yielding 15 overall publications.…”

“…All of the identified studies in this scoping review applied an observational study design, including four cross-sectional studies (yielding five publications) [ 19 , 21 , 22 , 24 , 28 ], three retrospective cohorts [ 14 , 17 , 27 ], two case-control studies [ 16 , 25 ], one cross-sectional study with an additional retrospective chart review [ 18 ], one retrospective chart review [ 26 ], one matched controlled cohort [ 23 ], one prospective cohort [ 20 ], and one case report [ 15 ]. No experimental studies were identified in the literature landscape.…”

“…The region producing the most publications (n = 3) on the topic of vitamin D and MM is the United States of America (USA) [ 14 , 19 , 26 ], with the majority of studies (n = 10) conducted in regions that are currently members of the OECD [ 14 , 15 , 17 , 18 , 19 , 20 , 24 , 26 , 27 , 28 ]. Eleven publications (ten conducted studies) reported on the prevalence of vitamin D deficiency (as a tally) among participants ( Table 3 ) [ 14 , 17 , 18 , 19 , 20 , 21 , 22 , 24 , 26 , 27 , 28 ], none reported on the risk of developing MM and vitamin D status, and eleven publications (ten conducted studies) reported on prognosis and/or clinical outcomes associated with vitamin D status [ 14 , 15 , 17 , 19 , 20 , 21 , 22 , 24 , 26 , 27 , 28 ]. Three publications explored the implications of VDR differences rather than vitamin D status in patients with MM [ 16 , 23 , 25 ].…”

“…The most common paired cutoff values within the same publication (n = 4) [ 18 , 21 , 22 , 27 ] were <20 ng/mL 25(OH)D (deficient) and >30 ng/mL 25(OH)D (sufficient). After conversion of ng/mL to nmol/L (and vice versa), the most common individual cutoff value for vitamin D deficiency from all publications was <50 nmol/L (<20 ng/mL) 25(OH)D (n = 9) [ 14 , 18 , 19 , 21 , 22 , 24 , 26 , 27 , 28 ] and >75 nmol/L (>30 ng/mL) 25(OH)D for vitamin D sufficiency (n = 6) [ 17 , 18 , 21 , 22 , 27 , 28 ]. The three publications that reported on VDR status did not assess vitamin D status against prespecified values [ 16 , 23 , 25 ].…”

“…Ten publications reported on the prevalence (as a tally) of vitamin D deficiency within their sample, applying the status definitions described in Table 2 [ 14 , 17 , 19 , 20 , 21 , 22 , 24 , 26 , 27 , 28 ]. A detailed report, including tallies and percentages, of vitamin D deficiency prevalence reported in each publication is described in Table 3 .…”