Dietary Sodium Intake and Urinary Sodium Excretion by Age Groups among Urban Dwellers

Transcription

1 Dietary Sodium Intake and Urinary Sodium Excretion by Age Groups among Urban Dwellers Associate Professor Dr. Hazreen B Abd Majid Department of Social and Preventive Medicine and Centre for Population Health, Faculty of Medicine, University of Malaya

2 Introduction Prevalence of hypertension worldwide Hypertension currently affects almost one billion people in the world and it was predicted that by 2025, 1.56 billion people will be hypertensive (Kearney et al., 2005). It has become a major cause of morbidity and mortality worldwide and it is now ranked third as a cause of disability adjusted life years (Ezzati, Lopez, Rodgers, Vander Hoorn, & Murray, 2002). The increases in hypertension are probably related to rapid social changes in our country and may apply to other areas of the developing world (Sun et al., 2010). 2

3 Introduction 100 Prevalence of hypertension in Malaysia 80 PERCENTAGE (%) ,7 32,2 32, NHMS II (1996) NHMS III (2006) NHMS 2011 YEAR There is an increasing trend in the prevalence of hypertension among the adult population in Malaysia. 3

4 Introduction According to Powles et al. (2013), in 2010: 1) The estimated mean intakes of sodium in 181 out of 187 countries, consisted 99.2% of the world adult population, exceeded the WHO recommendation of 2.00g/day sodium (~5 g/day salt). 2) Asian regions had the highest sodium intakes where I. Central Asia = 5.51g/day (14.01g of salt) II. Asia Pacific High Income (mainly Japan and South Korea) = 5.00g/day (12.71g of salt) III. East Asia = 4.80g/day (12.21g of salt) 4

5 Introduction 1) In 2003, the Ministry of Health, Malaysia, conducted the Malaysian Adult Nutrition Survey (MANS) and found out that the adults mean sodium intake was 2575mg/day which is equivalent to 6.4g of salt (Mohd Shariff, Mohd Yusof, & MY, 2008). 2) In addition, a study by Rashidah et al. (2014) reported that the mean urinary sodium excretion among the Ministry of Health staff was 142.0mmol/day which is equivalent to sodium intake of 3429mg/day or 8.7g of salt. Both studies showed that the salt intake in Malaysia is exceeding from the recommendation. 3) The aim of current study is to determine the level of dietary sodium intake and urinary sodium output and to show association between dietary sodium intake and urinary sodium output among the low income urban community.

6 Study design and study population 1) A cross sectional study at 2 randomly selected low income community housing projects (PPR) located in Lembah Pantai and Petaling Jaya. 2) All residents are eligible to participate, and all households will be invited to participate. 3) Household visit will be conducted and if the resident met the inclusion criteria, they will be recruited, upon given consent. Inclusion criteria Exclusion criteria Aged 18 years and above Have any chronic diseases (e.g. Kidney disease, Diabetes) Living in own house at least six months onward of study period Have known hypertensive or heart disease, with or without treatment Having mental illness 6

7 Study tools and measurement Socio demographic questionnaire Dietary assessment 24 hour urine collection 7

8 Results Variables Male (n=62) Female (n=118) Total (n=180) p value a) Socio demographic Age (Mean ± SD) ± ± ± b) Race Malay 57 (31.7) 105 (58.3) 162 (90.0) Chinese 3 (1.7) 8 (4.4) 11 (6.1) Indian 2 (1.1) 1 (0.6) 3 (1.7) Others 0 (0.0) 4 (2.2) 4 (2.2) c) Religion Islam 57 (31.7) 108 (60.0) 165 (91.7) Hindu 2 (1.1) 2 (1.1) 4 (2.2) Buddha 3 (1.7) 8 (4.4) 11 (6.1) Table 1: Sociodemographic, anthropometric, clinical and biochemical data of respondents

9 Results Variables Male (n=62) Female (n=118) Total (n=180) d) Level of education No formal education 1 (0.6) 6 (3.3) 7 (3.9) Primary school 10 (5.6) 17 (9.4) 27 (15.0) Lower secondary 13 (7.2) 22 (12.2) 35 (19.4) Upper secondary 29 (16.1) 52 (28.9) 81 (45.0) STPM/Diploma 7 (3.9) 7 (3.9) 14 (7.8) Don t know 2 (1.1) 14 (7.8) 16 (8.9) 39 % were not working, 29% working in private sector, 16% were self employed, 4% working with government and remaining were pensioner. Table 1: Sociodemographic, anthropometric, clinical and biochemical data of respondents

10 Results Variables Male (n=62) Female (n=118) Total (n=180) p value e) Anthropometry BMI (kg/m 2 ) (Mean ± SD) ± ± ± 5.49 <0.01 a Underweight (<18.5) 6 (3.3) 7 (3.9) 13 (7.2) Normal ( ) 16 (8.9) 15 (8.3) 31(17.2) Overweight ( ) 10 (5.6) 17 (9.4) 27 (15.0) Obese 1 ( ) 24 (13.3) 42 (23.3) 66 (36.7) Obese II ( 30.0) 6 (3.3) 37 (20.6) 43 (23.9) Table 1: Sociodemographic, anthropometric, clinical and biochemical data of respondents

11 Results Variables Male (n=62) Female (n=118) Total (n=180) p value f) Clinical SBP (mmhg) (Median ± IQR) ± ± ± Optimal (<120) 15 (8.3) 46 (25.6) 61 (33.9) Normal (<130) 25 (13.9) 29 (16.1) 54 (30.0) High normal ( ) 14 (7.8) 21 (11.7) 35 (19.4) Stage 1 ( ) 8 (4.4) 15 (8.3) 23 (12.8) Stage 2 ( ) 0 (0.0) 5 (2.8) 5 (2.8) Stage 3 ( 180) 0 (0.0) 2 (1.1) 2 (1.1) g) Biochemical Urinary sodium excretion (mmol/24h) ± ± ± (Median ± IQR) Table 1: Sociodemographic, anthropometric, clinical and biochemical data of respondents

12 Results Male (n=39) Female (n=82) Total (n=121) p value Dietary intake Energy intake (kcal/day) <0.01 a (Mean ± SD) ± ± ± Dietary sodium intake (mg/day) a (Mean ± SD) ± ± ± Table 2 : Dietary intake data of respondents

13 Results Table 3 : Comparing dietary sodium intake between age groups ( 40 years and >40 years) Variables 40 Mean (SD) n=25 >40 Mean (SD) n=96 Mean difference (95% CI) p value Sodium intake (mg/day) (775.60) (992.81) (32.99,880.42) In addition, there was no significant difference in urinary sodium excretion between those aged 40 and those above 40. The was a correlation between dietary sodium intake and urinary sodium excretion (r=0.17, p<0.01).

14 Discussion This study has shown that the sodium intake both from the dietary and excreted in urine in low income group is greater in male population compared to female. The intake of sodium estimated from the sodium excretion in urine was calculated by multiplying with the factor 100/95.Therefore, the median of urinary sodium excretion of the respondents were 91.1mmol/24hour which is equivalent to mg of sodium/day or 5.2g of salt/day. Meanwhile, the mean of dietary sodium intake of the respondents were ±967.0mg/day or equivalent to 9.3g of salt/day. The dietary intake of sodium of the respondents were almost doubled than the World Health Organization (WHO) recommendation which is less than 2g/day or equivalent to 5g of salt/day (WHO, 2012).

15 Discussion In this finding the dietary sodium intake was higher compared to the urinary sodium excretion. Limitations that may lead to current findings are: Usually the sodium excreted will be lesser than the actual sodium intake. Only 86% (Holbrook et al., 1984) to 95% (Vandervijvere et al., 2010) sodium will be excreted in the urine. Meanwhile, the other balance will be excreted through sweating and faeces due to exercise and high temperature climate (Kirby and Convertino, 1986). Thus, it reduces the amount of sodium obtained from the urine sample. Respondents may controlled their dietary intake prior the urine collection.

16 Discussion In this study, the highest sodium intake was found in the age group 40 while those aged >40 had lower intake. This result was consistent with the findings by the Health Promotion Board Singapore (2011) as they reported that age group of years had the highest sodium intake, while the intake of sodium among respondents aged 50 years and above were lower. There was a significant difference in systolic blood pressure among the age groups where the SBP in age group of >40 was higher compared to the younger aged group. In conclusion, the amount of sodium intake among the low income urban community were exceeding from the WHO recommendation. Therefore, interventions such empowering the knowledge and increase the awareness of the public, involving the industrial sector and policies maker in reducing the amount of salt content in food are necessary in order to reduce the amount of sodium consumption in the future.

17 Acknowledgement Team members: Ameera Abdul Thani, Tin Tin Su and Maznah Dahlui Grant UM Flagship 009/2011

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