The developmental origins of health and disease theory posits that early life experiences may be associated with adult chronic disease development, including obesity and cardiovascular diseases. Consequently, there has been interest in the associations between birth weight, body composition and chronic diseases, such as hypertension. At the 64th Annual Conference of the Caribbean Public Health Agency in 2017 it was noted that the Caribbean is in the midst of a childhood obesity epidemic with statistics showing that at least one in every 5 children carry unhealthy weight and is at risk for developing non-communicable diseases consequently, there has been a resurgence of interest in the associations between birth weight, body composition and chronic diseases, such as hypertension. The Caribbean Public Health Agency in 2017 noted that the Caribbean is in the midst of a childhood obesity epidemic with statistics showing that at least one in every 5 children carry unhealthy weight and is at risk for developing non-communicable diseases. Human growth during the first two years of life, that is, during infancy is a period of rapid postnatal growth which is not only accompanied by quantitative changes in body size but also major changes in body composition and it represents the best time for obesity prevention and other non-communicable diseases (NCDs) and their adverse consequences. Therefore, identification of effective early-life intervention targeting these modifiable factors is critical for paediatric, as well as adult obesity prevention and other NCD. However, few studies have examined the relationship between birth weight and body composition in one-year infants. While there are challenges to the birth weight hypothesis as a major contributor to the development of hypertension, in particular the consistently positive relationship of body weight with blood pressure (BP) throughout childhood and adulthood, substantial work has been done in this area of research and overall trends suggest a consistent relationship being that lower birth weight results in higher blood. This study will focus on the association between birth weight and body composition as well as the association of birth weight and blood pressure in one-year infants.
Problem Statement: An understanding of body composition in this early age group may be important in understanding human health and disease. Body composition can be divided into fat mass and fat-free mass. Early life factors such as birth weight have been suggested to play an important role in the development of various metabolic conditions A Birth weight of less than 2500g and over 4000g has shown to be associated with an increase in certain chronic adult disease, here is however there is a paucity of studies examining these relationships in children one year of age including obesity and hypertension, and so, there may be a possibility that these association may be evident from as early as one year of age.
Purpose Statement: The purpose of this study is to investigate if there is an association between birth weight and body composition as well as blood pressure in one-year old infants. A two-component model of body composition divides the body into a fat component and fat-free component. Body fat is the most variable constituent of the body. These associations will be examined by using the indirect methods of skin fold thickness and bio electrical impedance (BIA). Both methods will be used to calculate fat mass (FM) and fat free mass (FFM) or lean mass. The results of this study may indicate that there may be an association evident from as early as one year of age.
Significance of the Study: There is substantial evidence that the first 1000 days of an infant’s life is an important and plastic period during which events and exposures can have significant effects on a child’s development and his or her risk of many chronic non-communicable diseases later in life, including obesity, hypertension, and type 2 diabetes. (Moore, Arefadib, Deery, & West, 2017). This period is therefore an important time for monitoring and intervention for the prevention of ill health later on in life. The aim of this study is to investigate the association between birth weight and body composition as well as blood pressure in infants at one year old. Evidence of association between these factors at an early age may aid in developing preventative strategies to combat the development of non-communicable disease in later life.
The aim of this study is investigating the association between birth weight and body composition at one-year old as well as the association of birth weight and blood pressure in the infants. This study population will be infants living in Kingston and St. Andrew at one year of age.
1. To measure body composition in one-year old infants using BIA and skinfold thickness measurements.
2. To measure blood pressure in one-year old infants.
3. To perform anthropometric measurements in one-year old infants.
4. To explore the influence of birthweight on body composition and blood pressure at year old.
5. To explore the association, of body composition and blood pressure at one year old
1. Is there a relationship between birth weight and body composition at one year of age?
2. Is there a relationship between birth weight and blood pressure at one year of age?
3. Is there a relationship between body composition and blood pressure at one year of age?
Birth weight – is the first weight of new-born obtained after birth. For live births, birth weight should preferably be measured within the first hour of life, before significant postnatal weight loss has occurred.
Low birth weight – Low birth weight has been defined by the World Health Organization (WHO) as weight at birth of less than 2,500 grams (5.5 pounds).
Body composition – The percentage of fat, bone and muscle in the body, of which fat is of greatest interest.
Fat Free Mass (FFM)- Fat-free mass is used to describe all of the tissues in the body that are not adipose (fat) tissue. Fat-free body mass includes most of your body’s vital tissues and cells.
Fat Mass (FM)- The portion of the human body that is composed strictly of fat.
Blood pressure- blood pressure refers to the pressure of the blood within the arteries. It is produced primarily by the contraction of the heart muscle. Blood pressure measurement is recorded by two numbers. The first (systolic pressure) is measured after the heart contracts and is highest. The second (diastolic pressure) is measured before the heart contracts and lowest Elevation of blood pressure is called ‘hypertension.
A variety of methods have been developed for assessing body composition in infants, including isotopic determination of the total body water (the amount of water present in the body), radiography, potassium counting, bioelectrical impedance; where resistance and reactance are measured, anthropometry and others. These various techniques and models of assessing body composition in infants, the body is portioned into level and compartments where each level and its components are distinct. In these methods the body is divided into atomic, cellular, molecular, tissue-organ and whole body levels, each level is then divided into components of fat mass (FM), fat free mass(FFM), total body water (TBW), total protein(TPro), total potassium (K), etc. Practical means of measuring body composition in infants employ non-invasive and indirect methods. Two-compartment models at the molecular level divide the body into FM and FFM, such that TBW is the sum of FM and FFM. Body composition in children using this two-compartment model assessed by the indirect methods of skinfold thickness and bioelectrical impedance have been validated my many studies. These are the methods which will be employed in this study, thus, this literature review will be limited to what is published on body composition measure by these indirect methods This literature review will be organised by three themes, the relationship between birth weight and body composition in infants, the relationship between birthweight and blood pressure in infants and the overall relationship between all three variables. Methods employing a two-compartment model will be reviewed.
The interpretation of body composition has considered the important role of birth weight (BW); however, the body of literature report conflicting relationship. Normal birth weight for at term delivery, as defined by the World Health Organization is 2500-4200g. Singhal et al.(2003) in their study carried out in London provided evidence that birthweight does determine proportion of FM . Using skinfold-thickness measurement and bioelectrical impedance analysis 78 adolescents aged 13–16 years the study found that an increase in birth weight of one standard deviation was significantly associated with a 0.9–1.4-kg (2–3%) increase in FFM in adolescents, but birth weight showed no correlation with TBW. The study further compared these findings with that of 86 younger children and found that although the correlations were same for FFM, there was a positive correlation between birth weight and TBW in this younger age group. (Singhal, Wells, Cole, Fewtrell, & Lucas, 2003). Also using skinfold thickness measurements results from The Generation R Study carried out in 2009 showed that birth weight was inversely associated with truncal/peripheral fat ratio (p < 0.01) but not with relative body fat in early infancy. These findings of Singhal et al among younger children are consistent with the findings of the Brazilian Cohort study involving 486 children, 5 to 9 years of age and are also consistent with a cohort study among 176 Jamaican children, 9‒12 years of age in which body composition was assessed using bioelectrical impedance analysis (Taylor-Bryan, Badaloo, Boyne, Osmond, & Forrester, 2018). Further to evidence positive association relationships of birthweight with FFM and FM in children, Nsamba in 2019 using anthropometry and BIA showed that birthweight was associated with Fat mass index with a regression coefficient of 0.66, the study included 177 children aged 10-11 years and was carried out in Uganda.
In contrast to birth weight being associated to Fat mass J. Kagura, et. Al in their 2012 study found birth weight to be associated with Fat free mass, in that A one z-score increase in birth weight was associated with a 1051 g increase in lean mass. Koon and others also in the Birth Weight, Nutritional Status and Body Composition among Malaysian Children Aged 7 to 10 Years, found Birth weight has weak correlation (r =0.22,p < 0.01) (POH, 2013).Santos et al. showed no associated between birth weight and body composition, 7-year-old children they studied; however, this study did not consider gestational age, as a possible confounder.
Medical research has clearly established the relationship between birth weight, body composition and the prevalence of certain diseases in adults such as type 2 diabetes mellitus (T2DM), hypertension, hyperlipidaemia, metabolic syndrome, coronary artery disease (CAD), and certain types of cancer (National Heart, Lung, and Blood Institute, 1998). Diseases that were once considered to be “adult” diseases are now the diagnoses of many children and adolescents. Childhood blood pressure(BP) has been found to be a predictor of NCDs in young adults and adults alike, multiple studies have also suggested that birth weight may be one of the important determining factors of BP later in life.(Järvelin et al., 2004). Bonita Falkner did an extensive review of epidemiological data and found that overall, there tends to be a small but consistent relationship of lower birth weight with higher blood pressure (BP). For each kilogram increase in birth weight, the systolic BP is 1 to 2 mm Hg lower (Falkner, 2002). Lower birth weight is therefore shown to be associated with higher BP. In support of the findings of the previous study, one Longitudinal study of postnatal growth where blood pressure was measured half yearly from age 1 carried out in Jamaica showed that systolic blood pressure fell by 1.4 mm Hg for every 1-kg increase in birth weight (95% CI 0.2 to 2.7, P=0.02) and by 1.2 mm Hg.36. (Thame et al., 2000). In support of the findings from the Thame study and others mentioned. Woelk et.al in their ‘Birthweight and blood pressure among children in Harare, Zimbabwe’ study (1997) found that systolic blood pressure (SBP) was inversely associated with birthweight in the 756 children studied.(Woelk, Emanuel, Weiss, & Psaty, 1998). A weak inverse relationship between birth weight and blood pressure was observed Primataesta and others when they studied children aged 5 to 15 years in 2005 in England again supporting the inverse birthweight blood pressure relationship seen in other studies (Edvardsson, Steinthorsdottir, Eliasdottir, Indridason, & Palsson, 2012).
Blood pressure levels in children has also shown to be impacted by body composition (Lauer, Burns, & Clarke, 1985; Sinaiko, 1996) Wilks et. al (1999) in their large cross-sectional study of 2332 Jamaican children proved that BP in was associated with measures of FM and FFM with Pearson’s correlation coefficients ranging from 0.27 to 0.96 across age ranges. (Wilks et al.,1999). Another study carried out by Pamela Gaskins in Barbados showed that in children Fat mass was associated with diastolic blood pressure (DBP) but not systolic blood pressure (SBP) in some children and FFM was associated with both DBP and SBP in others overall showing that body composition impacts blood pressure in children. (Gaskin et al., 2015).
Overall, these results suggest conflicting relationship between birth weight and body composition measure such as FFM and total body mass and these differences in results may be age related. Furthermore, birth weight with blood pressure literature shows generally that the lower the birth weight the higher the systolic blood pressure, literature also shows that body composition and blood pressure in children are correlated. However, there is a paucity of studies examining these relationships in children one year of age.