[Estimation of the percentage of body fat based on the body mass index and the abdominal circumference: Palafolls Formula]. / Estimación del porcentaje de grasa corporal en función del índice de masa corporal y perímetro abdominal: fórmula Palafolls.

INTRODUCTION: Overweight and obesity have the features of a worldwide epidemic, making it a public health problem. The traditional classification with the body mass index is a good start, but after the evidence of the biochemical activities of adipose tissue, its measurement is a necessity. There are multiple formulas for this purpose, but with little possibility of applying it in Primary Care. The following formulas are proposed for its use in this setting; Men=(body mass index [BMI/Abdominal Circumference [AC]*10)+BMI. Women=([BMI/AC]*10)+BMI+10. MATERIAL AND METHODS: A descriptive, prospective study was conducted, including 505 women and 489 men aged between 30 and 90 years. Weight, height, and abdominal circumference were measured, and the body mass index, percentage of fat using the CUN BAE (Clínica Universidad de Navarra - Body Adiposity Estimator) and proposed formulas were calculated. RESULTS: Comparative calculations were made between CUN BAE and formulas. No significant differences were observed in the descriptive values (Women χ2=1.1; P=.89. Men χ2=0.8; P=.93. The confidence interval and standard error p=1. The numerical correlation shows r=0.94; p=0.0001; R2=0.89. The relative error of the mean in men was 5.48% and -0.43% in women. The comparison of medians demonstrated Wilcoxon=0.8333. The study of sensitivity and specificity for cut-off points shows a ROC curve AUC=0.986; P=<.0001. CONCLUSIONS: The lack of significant differences between the results of both formulas, makes it possible to be proposed for the calculation of the fat percentage in body weight in Primary Care Clinics.

[Estimation of body mass index based on brachial circumference in patients with permanent or temporary incapacity]. / Estimación del índice de masa corporal con base en la circunferencia braquial, para pacientes con discapacidad permanente o transitoria.

INTRODUCTION: Many patients are affected by various conditions, which make it impossible to calculate body mass index (BMI) by measuring weight and height. For this reason, the purpose of this study was to develop a mathematical tool that allows the approximate calculation of the brachial circumference for diagnosis and follow-up. The formula proposed for both sexes is: brachial circumference (cm)×30/32. Results≥28 must be added 2 points. MATERIAL AND METHODS: Prospective, descriptive, observational study performed in a primary care clinic, including 224 men and 248 women. Weight, height, brachial circumference, and BMI were calculated using Quetelet's formula and the proposed formula. RESULTS: In men, BMI (CI 95%)=0.63, while BCF (CI 95%)=0.49 (P=.95), while in women BMI (CI 95%)=0.73 and BCF (CI 95%)=0.56 (P=.95). The numerical ratio showed r=0.82, R2=0.67, P<.005. In percentages, 80.3% of the men (P=.01) had their results between 90 and 110%, in women it was 85.8% (P=.0001). The median comparison, obtained a Wilcoxon P=.83. According to diagnostic criteria of the World Health Organization (obesity, overweight, normal and malnutrition) a P=.95 was obtained in both sexes. CONCLUSIONS: The proposed formula has values with no significant difference in its results, with respect to Quetelet, being applicable in patients in special condition due to physical limitations for the measurement of weight and height for the calculation of BMI.