1. Anthropometric assessment of adults and elderly Dr. Dewan S. Alam, MBBS, MMedSc, PhD. Head, Non-communicable Disease Unit Health System & Infectious Diseases Division icddr,b
2. Why Anthropometric Assessment? Anthropometry is the measurement of body height, weight & proportions. It is an essential component of clinical examination of infants, children, pregnant women and adults. It is used to evaluate both under & over nutrition.
3. Anthropometric Measuresa. Height (cm) The subject stands erect & bare footed on a stadiometer with a movable head piece. The head piece is leveled with skull vault & height is recorded to the nearest 0.5 cm.b. Weight (kg) Use a regularly calibrated electronic or balanced-beam scale. Spring scales are less reliable. Weigh in light clothes, no shoes Read to the nearest 100 gm (0.1kg)
4. BMI measurement and nutritional status The international standard for assessing body size in adults is the body mass index (BMI).also termed Quetlet’s Index (Gibson, 2005, p 259) – Formula: BMI = Weight (kg)/ Height (m²)• Evidence shows that high BMI (obesity level) is associated with type 2 diabetes & high risk of cardiovascular morbidity & mortality.
6. WHO Expert Consultation for Asian• Proportion of Asian people with a high risk of type 2 diabetes and cardiovascular disease is substantial at BMIs lower than the existing WHO cut-off point for overweight (= 25 kg/m2).• Cut-off point for observed risk varies from 22 kg/m2 to 25 kg/m2 in different Asian populations and for high risk, it varies from 26 kg/m2 to 31 kg/m2 .Source: WHO expert consultation, 2004.
7. Indicators: (contd..)c. % body fat (BIA: Bioelectrical Impedance Analysis)• Widely used method for estimating body composition.• Relatively simple, quick, and noninvasive.• Determines the electrical impedance of body tissues, which provides an estimate of total body water (TBW).• Using values of TBW derived from BIA, one can then estimate fat-free mass (FFM) and body fat (adiposity). (Macias et al., 2007; NIH, 1994)
8. Indicators: (contd..)• Skinfold thickness measurements provide an estimate of the size of the subcutaneous fat depot, which in turn, provides an estimate of total body fat. (Gibson, 2005)• Skinfold thickness and arm circumference are two measurements that indirectly assess two important components of a body: – Fat and fat-free mass. – Cause, the main storage form of energy and fat-free mass, usually muscle, is a good indicator of the protein reserves of a body.
9. Indicators: (contd..)d. Skinfolds: – Triceps skinfold: Measured at the mid point of the back of the upper arm – Biceps skinfold: Measured as the thickness of a vertical fold on the front of the upper arm, directly above the center of the cubital fossa, as the same level as the triceps skinfold. (Gibson, 2005)
10. d. Skinfolds: (Contd..)– Subscapular skinfoldMeasured below and laterally to the angle ofthe shoulder blade, with the shoulder andarm relaxed. Placing the subjects arm behindthe back may assist in identification of thesite. The skin fold should angle 45 degreefrom horizontal, in the same direction as theinner border of the scapula.– Suprailiac skinfoldMeasured in the mid axillary lineimmediately superior to the illiac crest. Theskinfold is picked up obliquely just posteriorto the mid axillary line and parallel to thecleavage lines of the skin. (Gibson, 2005)
11. Indicators: (contd..)e. Mid Arm Circumference (MAC) (cm) g. Hip Circumference (Hip) (cm) – Measured at the point of greatest circumference around hips & buttocks to the nearest 0.5 cm. Waist–hip ratio or waist-to-hip ratiof. Waist Circumference (Wst) (cm) (WHR) is the ratio of the circumferenceWaist circumference is measured at the level of the waist to that of the hips.of the umbilicus to the nearest 0.5 cm. – Formula= Waist:Hip Ratio = Wst/Hip
12. Chronic energy deficiency• To identifying CED affected individuals involves – measuring body weight and height, – then energy intake (or expenditure) and – basal metabolic rate (BMR). BMI < 16.0 16.0-16.9 17.0-18.4 > 18.5 CED grade III II I NormalSource: James et al., 1988; Shetty & James, 1994
13. Over weight & Obesity• The overweight and obesity group defined overweight as - – Obesity related to a BMI of 25–29.9 kg/m2 (grade 1), – With grade 2 overweight commonly termed as obesity specified for a BMI of 30–39.9 kg/m2, – Grade 3 or morbid obesity as applying to those with BMI ≥ 40 kg/m2. (James, 2008)• Obesity is associated with a rapid increase in health problems such as CVD and diabetes. (Engelgau et al., 2011)
14. Weight Gain in Pregnancy - Physiology• 27.5 lbs (12.5 kg) is “normal” physiologic gain (Hytten 1991)• 9 kg (~20 lbs) is made up of fetus, placenta, amniotic fluid, uterine/breast hypertrophy, increased blood volume and retained fluid• 3.5 kg (7.5 lbs) is maternal storage fat
15. Weight Gain in Pregnancy - Physiology• 27.5 lbs (12.5 kg) is “normal” physiologic gain (Hytten 1991)• 9 kg (~20 lbs) is made up of fetus, placenta, amniotic fluid, uterine/breast hypertrophy, increased blood volume and retained fluid• 3.5 kg (7.5 lbs) is maternal storage fat
16. Pregnancy Weight Gain Recommendations in the U.S. - History• 19th century - restriction of food intake to prevent difficult labor• 1901 - first published study of diet and birth weight – restricted food intake linked to lower BW• 1920’s – more studies associating weight gain and BW
17. Pregnancy Weight Gain Recommendations in the U.S. - History• 1971 – Hytten and Leitch published review of studies from 1950’s and 60’s• Average gain of 12.5 kg (27.5 lbs) is “physiologic normality” in healthy young primigravid women• Association between pre-pregnancy weight, weight gain, and birth weight noted in literature• 1970 – National Academy of Sciences Food and Nutrition Board’s Committee on Maternal Nutrition: 20-25 lbs recommended Associated with low weight gain: – Infant mortality – Disability – Mental retardation
18. Pregnancy Weight Gain Recommendations in the U.S. - History• 1972 – ACOG also endorsed the 20-25 lb guideline• 1981 – FNB’s Nutrition Services in Perinatal Care: Inadequate gain = 1kg or less/month in 2nd and 3rd trimesters, Excessive gain = 3kg or more/month
19. What outcomes have been associated with pregnancy weight gain?• Birth weight – SGA/IUGR – LGA/macrosomia >>maternal morbidities• Mode of delivery• Preterm birth• Postpartum weight retention
20. Weight Gain and Birth Weight• Well-established relationship, even when using net weight gain (total weight gain minus birth weight of infant)• Relationship seems to be modified by pre- pregnancy body mass index• Controversy about relationship between weight gain and birth weight among obese women
21. The IOM Report and GuidelinesIOM Recommendations for Weight Gain in Pregnancy (1990) Pre-pregnancy Body IOM Recommended Mass Index Gestational Weight Gain (lbs/kg) <19.8 (Low) 28-40 / 12.5-18 19.8 - 26.0 (Normal) 25-35 / 11.5 - 16 26.1 - 29.0 (High) 15-25 / 7 – 11.5 >29.0 (Obese) At least 15 / At least 6
22. The IOM Report and Guidelines• Retrospective, observational data• First widely-accepted guidelines, BMI- specific• Controversy over guidelines: too high, too low.• ~ 30 – 40 % of all women• To date: The range for best outcome of the infant
23. Weight gain recommendations in Europe & Asia Austria: Max. 15 kg weight gain Denmark: IOM guidelines Finland: 15 kg for normal weight women Germany: No official guidelines Switzerland: No official guidelines UK: Not weighing during pregnancy Hong Kong: BMI specific weight gain recommendations No information available: France, Italy, Spain, Sweden
24. Weight Gain and Macrosomia• Strongly associated• Most cases of macrosomia occur in non-diabetic women• Macrosomia is associated not just with infant trauma, but with multiple increased risks of maternal morbidity: cesarean birth, severe perineal lacerations, peripartum infection, and prolonged hospital stay (even among those delivering vaginally)
25. Weight Gain and Cesarean Birth• High weight gain is associated with increased risk of both prolonged labor and cesarean birth• This relationship is only partly attributable to higher birth weight• Even when birth weight controlled for in multivariate analysis, high weight gain is an independent risk factor for cesarean birth
26. Weight Gain and Preterm Birth• Multiple epidemiologic studies have associated poor gestational gain with increased risk of preterm birth• Obvious confounder of length of gestation as well as birth weight – most studies have addressed this• Most studies have not stratified by pre- pregnancy BMI, some excluded obese women
27. Weight Gain and Preterm Birth Study - Results• Low BMI group gaining below guidelines had PTB rate of 5.9% vs. 3.5% for those gaining within guidelines (P< 0.001)• High BMI group gaining below guidelines had PTB rate of 8.1% vs. 3.8% for those gaining within guidelines (P<0.001).• Normal BMI group gaining below guidelines had PTB rate of 5.2% vs. 3.4% for those gaining within guidelines (P<0.001).
28. Gestational Weight Gain – Methodologic Challenges• What measure of weight gain to use?• How reliable are self-reported weights?• Gestational age assessment• Race/ethnicity variation• Limitation of retrospective/epidemiologic data• Optimal weight gain depends on the outcome one studies
29. What can we do? Do interventions work?• Historically: guidelines/provider advice can impact actual weight gain• Few studies have linked interventions to outcomes beyond #kg gained
30. Interventions• By-mail patient education• Regular clinical meetings for education with goal-setting• Phone calls between visits• Newsletters• Personal graph of weight gain
31. Goals for Future Research• Achieve adequate weight gain in pregnancy• Studies in overweight/obese women• Qualitative research – patient and provider attitudes, beliefs• RCTs of novel interventions – both weight gain and other outcomes – low glycemic load diet trial – Janet King PI
32. Why is weight gain important during pregnancy?• The extra weight during pregnancy provides – Nourishment to developing baby – Stored for breastfeeding baby after deliveryPicture Source: (WHO, 2011; p 17)
33. New Recommendations for Total and Rate of Weight Gain During Pregnancy, by Prepregnancy BMI The guidelines and supporting recommendations are intended to be used in concert with good clinical judgment and should include a discussion between the woman and her care provider about diet and exercise. Developed by WHO and adopted by NHLBI. Source: Rasmussen, & Yaktine, 2009; Rasmussen et al., 2009.
34. Data availability on Information and Accountability for Woman’s and Children’s HealthWHO, (2011). Monitoring maternal, newborn and child health: understanding key progress indicators. p 15.
35. Strengthening countries’ capacity to monitor and evaluate results• High quality data are critically needed in order to enable global assessment of progress on the Commission’s recommended measures of coverage, impact, financing, and equity related to women’s and children’s health.• The availability of accurate, timely, and consistent data at the national and sub-national levels is crucial for countries to be able to effectively manage their health systems, allocate resources according to need, and ensure accountability for delivering on health commitments. (WHO, 2011, p 13)
36. ADVANTAGES OF ANTHROPOMETRY• Objective with high specificity & sensitivity• Measures many variables of nutritional significance (Ht, Wt, MAC, HC, skin fold thickness, waist & hip ratio & BMI).• Readings are numerical & gradable on standard growth charts.• Readings are reproducible.• Non-expensive & need minimal training
37. Limitations of Anthropometry• Inter-observers errors in measurement• Limited nutritional diagnosis• Problems with reference standards, i.e. local versus international standards.• Arbitrary statistical cut-off levels for what considered as abnormal values.