Proposal of MUAC as a fast tool to monitor pregnancy nutritional status: results from a cohort study in Brazil.

OBJECTIVE: In Brazil, although the assessment of maternal nutritional status is recommended using body mass index (BMI), this is only possible in settings adequately prepared. Midupper arm circumference (MUAC) is another biological variable identified as a tool for rapid assessment of nutritional status that is correlated with BMI. Therefore, we aim to surrogate BMI by MUAC cut-offs for rapid screening of maternal nutritional status starting at midpregnancy. DESIGN: Analysis of the multicentre cohort study entitled 'Preterm SAMBA' using an approach of validation of diagnostic test. SETTING: Outpatient prenatal care clinics from five tertiary maternity hospitals from three different Brazilian regions. PARTICIPANTS: 1165 pregnant women attending prenatal care services from 2015 to 2018 and with diverse ethnic characteristics who were enrolled at midpregnancy and followed in three visits at different gestational weeks. PRIMARY AND SECONDARY OUTCOME MEASURES: Sensitivity, specificity, positive and negative predictive values, likelihood ratio and accuracy of MUAC being used instead of BMI for the assessment of nutritional status of women during pregnancy. RESULTS: We found a strong correlation between MUAC and BMI, in the three set points analysed (r=0.872, 0.870 and 0.831, respectively). Based on BMI categories of nutritional status, we estimated the best MUAC cut-off points, finding measures according to each category: underweight <25.75 cm (19-39 weeks); overweight 28.11-30.15 cm (19-21 weeks), 28.71-30.60 cm (27-29 weeks) and 29.46-30.25 cm (37-39 weeks); and obese >30.15 cm (19-21 weeks), >30.60 cm (27-29 weeks) and >30.25 cm (37-39 weeks) per gestational week. Therefore, we defined as adequate between 25.75-28.10 cm (19-21 weeks), 25.75-28.70 cm (27-29 weeks) and 25.75-29.45 cm (37-39 weeks) of MUAC. CONCLUSION: We conclude that MUAC can be useful as a surrogate for BMI as a faster screening of nutritional status in pregnant women.

Morphological changes in rat rectus abdominis muscle induced by diabetes and pregnancy

The urethral muscle of diabetic pregnant rats is affected by long-term mild diabetes and short-term severe diabetes, which plays a crucial role in the pathogenesis of pelvic floor disorders. We hypothesized that muscles outside the pelvis are subject to similar changes. The current study aimed at analyzing the effects of long-term mild and short-term severe diabetes on the structure and ultrastructure of fiber muscles and collagen in rats' rectus abdominis (RA) muscle. Therefore, the RA muscle of virgin, pregnant, long-term mild diabetic, short-term severe diabetic, long-term mild diabetic pregnant and short-term severe diabetic pregnant 3-month-old Wistar rats were collected. The structure was analyzed by picrosirius red staining, immunohistochemistry for fast and slow muscle fibers and transmission electron microscopy. We investigated two levels of STZ- induced diabetes: long-term mild diabetes (blood glucose level: 120-200 mg/dL) and short-term severe diabetes (blood glucose level >300 mg/dL). Long-term mild diabetic pregnant and short-term severe diabetic pregnant rats had decreased fast fibers and increased slow fibers, disrupted areas of sarcomere, intermyofibrillar mitochondria and myelin figures in the RA muscle. Both groups enabled us to analyze the specific influence of pregnancy, separately from diabetes. The current study demonstrated that diabetes and pregnancy induced intramuscular transformation and reorganization of RA muscle with a switch of fiber type adjusting their architecture according to intensity and duration of hyperglycemic insult within pregnancy.