Relationship of body mass index to percent body fat determined by deuterium isotopic dilution and impedancemetry among Tunisian schoolchildren.

Objectives: This study aims to evaluate the relation of body mass index (BMI) to fat mass among children by two techniques impedancemetry and deuterium oxide dilution (D2O). Methods: This study was carried out in 156 schoolchildren aged between 8 and 11 years. The children received interrogation specifying lifestyle and food habits. Body composition was determined using the impedancemetry and D2O technique. Results: The results showed a difference between the percentage of obese and overweight children according to BMIZ classification (30.1%), bioelectrical impedance method (14.7%) and D2O technique (42.9%). Despite the difference between the last two classifications, we found a significant correlation between body fat percentages determined by impedancemetry and D2O technique (r = 0.695, p<0.01). Bioelectrical impedance analysis underestimated %BF by 78.02% in overall children, by 70.05% in boys and by 84.73% in girls compared to D2O technique. Conclusion: This study has demonstrated that the percentage of overweight and obesity varied according the methods used. Further development of body composition methods is needed in children for the real determination of the obesity prevalence and therefore a better monitoring of this public health problem.

Coding-Complete Genome Sequences of a Delta Subvariant (AY.33) of SARS-CoV-2 Obtained from Moroccan COVID-19 Patients.

We report here the complete genome sequences of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strains obtained from Moroccan patients with COVID-19. The analysis of these sequences indicates that the identified strains belong to the AY.33 sublineage of the Delta variant.

Comparison of a fluorometric assay kit with high-performance liquid chromatography for the assessment of serum retinol concentration.

BACKGROUND: Although high-performance liquid chromatography (HPLC) is the commonly used method for the analysis of retinol in biological samples, simple and rapid test kits are available. OBJECTIVES: This study compared a rapid test kit (ICHECK Fluoro®) to HPLC for the assessment of serum retinol concentrations. METHODS: For the analysis by HPLC, sample preparation included standard deproteinization and extraction phases. The analysis by ICHECK was performed by injecting serum into IEX reagent vials (n=89) and mixing manually for separation. After precipitation of the proteins, the vial was introduced into the chamber of the ICHECK Fluoro and analysed at 0 min (ICHECK0min) and 15 min later (ICHECK15min). Bland and Altman approach was applied to test the agreement between HPLC and ICHECK. RESULTS: Mean HPLC, ICHECK0min and ICHECK15min values were 421.2±106.0 µg/L, 423.1±118.3 µg/L and 413.2±107.6 µg/L, respectively. Retinol concentrations significantly decreased in the IEX solution over time (p<0.001). No significant proportional bias was observed between HPLC and ICHECK0min (r-0.038, p=0.73) and ICHECK15min (r=-0.024, p=0.82). Fixed biases (HPLC minus ICHECK) for ICHECK0min and ICHECK15min were respectively -1.9±23.1 µg/l (p=0.45) and 8.0±22.7 µg/l (p=0.002). CONCLUSION: ICHECK Fluoro may offer a reliable mean for assessing serum retinol for measurements performed with no significant time delay.