Obesity in relation to conventional and novel metabolic risk factors in urban Kenya Lydia Kaduka (PhD) Centre for Public Health Research Kenya Medical Research Institute

Introduction In Kenya, NCD accounts for >50% of total hospital admissions and over 55% of hospital deaths (MOH SP, 2014) Overall, CVDs, diabetes, cancer and chronic lung disease contribute to over two thirds of morbidity & mortality from NCDs in Kenya (WHO 2010). Leading CVDs RFs Conventional - high blood pressure, dyslipideamia, tobacco and alcohol use, physical inactivity, obesity, unhealthy diets and raised blood glucose Novel – homocysteine, CRP Obesity - associated with CVDs, diabetes and cancers → ↑risk of premature death and disabilities → reduced quality of life. It is true that the burden and threat of NCDs pose a major challenge to the social to the social economic fabric of many countries and Kenya is no exception. 1. Obesity increases the risk of morbidity from hypertension, dyslipidemia, diabetes, coronary heart disease, stroke, gall bladder disease, osteoarthritis, sleep apnea and respiratory problems, and some cancers. 2. Obesity is also associated with an increased risk of all-cause and CVD mortality. It is a key risk factor of CVDs 3. Hcy independently predicts progression of coronary plaque burden irrespective of conventional risk factors 4. Hcy (aa) is a key branch-point intermediate in the ubiquitous methionine cycle and connects to the folate cycle, glycolysis pathway, and urea cycle. 5. Hcy activates platelet function, endothelial leukocyte interaction, and enhances inflammatory response responsible for atherosclerotic disease 6. CRP is an innate immune response protein produced mainly by hepatocytes 7. CRP downregulates endothelial NO synthase, upregulates adhesion molecules 8.

Potential mechanisms linking obesity to hypertension, diabetes and cancer Excess intra-abdominal fat (visceral adiposity) is linked to excess morbidity and mortality, and positively correlates with the risks of insulin resistance, type 2 diabetes, cardiovascular diseases, certain cancers, and premature death. (Narkiewicz, 2006)

Objective To assess the relationship between obesity and conventional and novel metabolic risk markers in an urban population in Kenya

Methodology –Design Study site – Kibra and Karen Constituency of Nairobi County – hosts all the five SEC (Upper, Lower Upper, Middle, Lower Middle and Lower class). Study design: Cross sectional design based on a three-stage cluster sampling methodology – selection of clusters, households and respondents.

Sample size and sampling Sample size – 536 (Fisher et al., 1983) Sampling – 30 clusters sampled using the systematic Probability Proportional to Size (PPS) sampling method Inclusion – adults aged >18yrs, absence of debilitating disease, residence>2years

Sampling Procedure Kibra and Karen Constituencies Upper Upper Middle Middle Upper Lower Lower Quick Count of EA Select one Segment Identify Eligible Respondents Select one Respondent from the Eligibles per Household Interview and testing

Assessments Socio-economic and demographic assessments Anthropometric assessments – weight, height (BMI), WC Clinical examination- blood pressure Biochemical assessments – fasting blood glucose, lipid profile, homocysteine and CRP Permission – Ethical (KEMRI SERU) and informed consent

Findings Total n = 539 (m: 50.5%; w: 49.5%); mean age 38.09 + 13.4 years. Prevalence of overweight (BMI 25.0-29.99) m: 29.6%; w: 5.9% Prevalence of obesity (BMI>30) m: 30.3%; w: 27.3%

Association between BMI and CVD RF Men Women Increased blood pressure P=0.003 P=0.010 Fasting blood glucose P<0.001 C-reactive protein P>0.05 P=0.002 Homocysteine Total cholesterol LDLC HDLC TAG SES Increasing age

Association between WC and CVD RF Men (WC>95cm) Women WC (80cm) Increased blood pressure P<0.001 P=0.010 Fasting blood glucose P=0.036 C-reactive protein P>0.05 P=0.032 Homocysteine P=0.021 P=0.025 Total cholesterol p= 0.004 LDLC HDLC P=0.002 TAG SES Increasing age

Conclusions Prevalence of CVD risk factors is high - consequence of components associated with urbanization Components More than an economic issue Changes in lifestyle related factors, living conditions, social structures etc, associated with and induced by urbanization as probable contributing factors Accelerated effects of cultural and behavioral shifts in transitional societies Need to determine the right paths for tackling obesity, which requires a paradigm shift in thinking and combined approaches. Incorporate new nutritional and physical strategies

Recommendations Lifestyle management focusing on diet and physical activity. Gender disparities → Patient-physician discussions of individual risks are paramount Simple measures should be adapted as clinical components in the routine assessment and management of metabolic and cardiovascular risks Risk factors operate in continuum - follow up longitudinal studies and prospective validation of the risk factors. 1. 2. 3. Measure waist circumference at least annually in overweight and obese adults. The greater the waist circumference, the greater the risk of CVD, type 2 diabetes, and all-cause mortality 4.

Acknowledgements KEMRI Kenya National Bureau of Statistics Administration-Karen and Kibra Constituencies University of Southampton Coca-Cola Company