Prevalence of 25-OH-Vitamin D and Calcium Deficiency in Adolescent Idiopathic Scoliosis

Interrogating Causal Effects of Body Composition and Puberty-Related Risk Factors on Adolescent Idiopathic Scoliosis: A Two-Sample Mendelian Randomization Study

Adolescent idiopathic scoliosis (AIS) is the most common form of pediatric musculoskeletal disorder. Observational studies have pointed to several risk factors for AIS, but almost no evidence exists to support their causal association with AIS. Here, we applied Mendelian randomization (MR), known to limit bias from confounding and reverse causation, to investigate causal associations between body composition and puberty-related exposures and AIS risk in Europeans and Asians. For our two-sample MR studies, we used single nucleotide polymorphisms (SNPs) associated with body mass index (BMI), waist-hip ratio, lean mass, childhood obesity, bone mineral density (BMD), 25-hydroxyvitamin D (25OHD), age at menarche, and pubertal growth in large European genome-wide association studies (GWAS), and with adult osteoporosis risk and age of menarche in Biobank Japan. We extracted estimates of the aforementioned SNPs on AIS risk from the European or Asian subsets of the largest multiancestry AIS GWAS (N = 7956 cases/88,459 controls). The results of our inverse variance-weighted (IVW) MR estimates suggest no causal association between the aforementioned risk factors and risk of AIS. Pleiotropy-sensitive MR methods yielded similar results. However, restricting our analysis to European females with AIS, we observed a causal association between estimated BMD and the risk of AIS (IVW odds ratio for AIS = 0.1, 95% confidence interval 0.01 to 0.7, p = 0.02 per SD increase in estimated BMD), but this association was no longer significant after adjusting for BMI, body fat mass, and 25OHD and remained significant after adjusting for age at menarche in multivariable MR. In conclusion, we demonstrated a protective causal effect of BMD on AIS risk in females of European ancestry, but this effect was modified by BMI, body fat mass, and 25OHD levels. Future MR studies using larger AIS GWAS are needed to investigate small effects of the aforementioned exposures on AIS. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Incidence of vitamin D deficiency in adolescent idiopathic scoliosis: a meta-analysis

Introduction

This study aimed to investigate the incidence of vitamin D deficiency in patients with adolescent idiopathic scoliosis through a meta-analysis and to analyze trends and risk factors.

Methods

Potentially relevant studies were searched using the terms "Vitamin D AND scoliosis." Data on the incidence and risk factors, such as race, curve magnitude, and sex, were extracted from the selected studies. Review Manager 5.4 software was used for the data analysis. Six studies with a total of 1, 428 patients met the inclusion criteria.

Results

The incidence of vitamin D insufficiency in patients with idiopathic scoliosis was 36.19% (95% CI [21.93 to 50.46]. In contrast, the incidence of vitamin D deficiency was 41.43% (95% CI [16.62 66.23]. Vitamin D levels were compared between Caucasian and African patients and it was concluded that Caucasian patients had a lower risk of vitamin D deficiency [RR 0.15, 95% CI (0.03 to 0.82; P = 0.03]. There was also an association between patients with idiopathic scoliosis and lower vitamin D -5.58, 95% CI [-7.10, -4.06]. Finally, no significant differences were observed in terms of curve magnitude assessed with the Cobb angle mean difference (MD) 4.45, 95% CI [-0.55, 9.44], or sex with lower-than-normal levels of vitamin D OR 0.96, 95% CI [0.58 to 1.60].

Discussion

The incidence rates of vitamin D insufficiency and deficiency in patients with adolescent idiopathic scoliosis were 36.19% and 41.43%, respectively. The Caucasian race was associated with a lower risk of vitamin D deficiency compared to the African race. Vitamin D deficiency was not related to curve magnitude or sex.

Metabolic Imbalances and Bone Remodeling Agents in Adolescent Idiopathic Scoliosis: A Study in Postmenarcheal Girls

The causes and mechanisms underlying adolescent idiopathic scoliosis (AIS) remain unclear, and the available information regarding metabolic imbalances in AIS is still insufficient. This investigation aimed to evaluate the concentrations of specific bone remodeling-related agents in postmenarcheal girls diagnosed with AIS. The study encompassed thirty-six scoliosis patients and eighteen age-matched healthy individuals assigned to the control group. The patients underwent clinical and radiological examinations to assess the degree of the spinal deformity, type of curvature, and skeletal maturity. Blood and urine samples were collected from all participants and serological markers were measured using an enzyme-linked immunosorbent assay. Our study results demonstrated that the balance of phosphate-calcium and parathormone levels seems normal in individuals with AIS. Furthermore, no statistically significant differences were observed in the content of Klotho protein, osteocalcin, osteoprotegerin, C-terminal telopeptide of type I collagen (CTX), sclerostin, and alkaline phosphatase. Nevertheless, the serum levels of vitamin D (25-OH-D) were lowered, while N-terminal propeptide of type I procollagen (PINP), and fibroblast growth factor-23 (FGF23) were increased in the AIS group, with p-values of 0.044, 0.001, and 0.022, respectively. This finding indicates the potential involvement of these factors in the progression of AIS, which necessitates further studies to uncover the fundamental mechanisms underlying idiopathic scoliosis.

Do Adolescent Idiopathic Scoliosis Patients With Vitamin D Deficiency Have Worse Spine Fusion Outcomes?

BACKGROUND

Prior research has shown that patients with adolescent idiopathic scoliosis (AIS) have a higher prevalence of vitamin D deficiency compared with healthy peers. In adult orthopaedic populations, vitamin D deficiency has been shown to be a risk factor for higher reported pain and lower function. We investigated whether there was an association between vitamin D levels and AIS patient-reported outcomes, as measured by the Scoliosis Research Society (SRS-30) questionnaire.

METHODS

This was a single-center, cross-sectional study. Postoperative AIS patients were prospectively recruited during routine follow-up visits, 2 to 10 years after spine fusion. Vitamin D levels were measured by serum 25-hydroxyvitamin D (ng/mL). Patients were categorized based on vitamin D level: deficient (<20 ng/mL), insufficient (20 to 29 ng/mL), or sufficient (≥30 ng/mL). The correlation between vitamin D levels and SRS-30 scores was analyzed using multivariable analysis and pair-wise comparisons using Tukey method.

RESULTS

Eighty-seven AIS patients (83% female) were enrolled who presented at median 3 years (interquartile range: 2 to 5 y; range: 2 to 10 y) after spine fusion. Age at time of surgery was mean 15 (SD±2) years. Major coronal curves were a mean of 57 (SD±8) degrees preoperatively and 18 (SD±7) degrees postoperatively. It was found that 30 (34%) of patients were vitamin D sufficient, 33 (38%) were insufficient, and 24 (28%) were deficient. Although there was no correlation between vitamin D level and Pain, Mental Health, or Satisfaction domains ( P >0.05), vitamin D-deficient patients were found to be younger ( P <0.001) and had lower SRS-30 function ( P =0.002), Self-image ( P <0.001), and total scores ( P =0.003).

CONCLUSIONS

AIS patients with vitamin D deficiency (<20 ng/mL) are more likely to be younger age at time of surgery, and report lower Function, Self-image, and Total SRS-30 scores postoperatively. Further work is needed to determine whether vitamin D supplementation alters curve progression and patient outcomes.

LEVEL OF EVIDENCE

Level II-prognostic study.

Vitamin D-A Risk Factor for Bone Fractures in Children: A Population-Based Prospective Case-Control Randomized Cross-Sectional Study

BACKGROUND

Vitamin D is an essential component in calcium metabolism. Seasonality, advanced age, sex, dark skin pigmentation, and limited exposure to sunlight were reported as causes of vitamin D deficiency. This study aims to determine whether children with lower levels of vitamin D suffer more fractures than those with sufficient levels.

MATERIALS AND METHODS

Our institution underwent a prospective case-control randomized cross-sectional single-blinded study that included 688 children. They were split into two groups: the study group and the control group. The study group received supplements of vitamin D and calcium for 6 months. Another reference cohort was observed, which comprised 889 patients in the pediatric ward for different respiratory or gastroenterological conditions without a history of fractures. This group was used for age-sex matching tests.

RESULTS

Logistic regression showed that with every one unit increase of vitamin D level, the chance of having a middle third fracture in both bones of the forearm decreased by 7% (OR 1.07); distal third fracture incidence decreased by 1.03 times; middle third radius fracture incidence decreased by 1.03 times; distal third radius fracture incidence decreased by 1.06 times. The risk of having a distal third both-bone forearm fracture increased by 1.06 times with every year of age. Comparing the healing process, we noticed an improvement in bony callus formation for patients in the study group.

CONCLUSIONS

Dosing the serum level of 25-OH-vitamin D should be taken into consideration for pediatric low-energy trauma fractures. Supplementing with vitamin D and calcium throughout childhood can be a solution for healthy bones. Our preliminary results show that the normal level of vitamin D in children should start at 40 ng/mL.