Correlation of Head Circumference with Body Mass Index in A Group of Elderly Sri Lankan Population

Introduction: Accurate estimation of the body mass index (BMI) is important in assessing nutritional status, risk of myriad of medical conditions including hypertension, coronary heart disease, adult-onset diabetes mellitus and dementia. However, emergency settings and immobility make it difficult to obtain personal stature and weight using standard methods. Thus, the need for an alternate method of BMI prediction arises. Objective: Goal of this study was to propose population, age and gender specific regression formula for BMI estimation using HC for an elderly Sri Lankan population. Material & methods: Personal stature, weight and HC was recorded in a total of 156 cadavers (age: 55 – 89 years);(male: n=74; female: n=82). Results: The HC (cm) (male: 54.09 ± 3.28; female: 52.88 ± 2.83) was significantly different (P< 0.01) between the genders. There was no statistically significant difference between mean BMI (Kg/m2) of male (20.32 ± 4.08) and female (20.93 ± 2.20). Correlation coefficient between HC and BMI was 0.09 in males and 0.04 in females indicating a weak positive linear relationship between the two parameters. Linear regression formulae for the prediction of BMI using HC were derived as follows: male: 14.04 + 0.15(HC); female: 20.03 + 0.02(HC).Discussion: BMI prediction formulae that require a measuring tape as the only tool to record the HC provide a simple, cost effective and objective method for patients who are unable to stand or weighed. Accurate prediction of BMI will in turn reduce potential errors in pharmacological interventions that may occur when it is estimated only by visual observation in emergency settings. Complementary studies are necessary to evaluate the applicability of these equations in other age groups too.