Myo-inositol, glucose and zinc status as risk factors for non-syndromic cleft lip with or without cleft palate in offspring: a case-control study.

Objective: To investigate myo-inositol, glucose and zinc status in mothers and their infants on cleft lip with or without cleft palate risk (CLP).

Design: Case-control study.

Setting: University Medical Centre Nijmegen, the Netherlands.

Population: Eighty-four mothers and their CLP child and 102 mothers and their healthy child.

Methods: Venous blood samples were obtained to determine serum myo-inositol and glucose and red blood cell zinc concentrations in mothers and children. Geometric means were calculated and compared between the groups. The blood parameters were dichotomised with cutoff points based on control values, P90 for glucose concentrations.

Main Outcome Measures: Geometric means (P5-P95) and odds ratios (95% confidence intervals).

Results: The CLP children (P= 0.003) and their mothers (P= 0.02) had significantly lower red blood cell zinc concentrations than controls. A low maternal serum myo-inositol concentration (<13.5 micromol/L) and a low red blood cell zinc concentration (<189 micromol/L) increased CLP risk [odds ratio 3.0 (95% CI 1.2-7.4) and 2.0 (95% CI 0.8-4.8), respectively]. Children with low myo-inositol (<21.5 micromol/L ) or low red blood cell zinc concentrations (<118 micromol/L) were more likely to have CLP [odds ratio 3.4 (95% CI 1.3-8.6) and 3.3 (95% CI 1.3-8.0), respectively]. Glucose was not a risk factor for CLP in mothers and children. Maternal and child myo-inositol as well as zinc concentrations were slightly, albeit significantly correlated, r(Pearson)= 0.33 (P= 0.0006) and r(Pearson)= 0.23 (P= 0.01), respectively.

Conclusion: This study demonstrates for the first time that zinc and myo-inositol are important in the aetiology of CLP.