4 Physical measurements
4.3 Blood pressure
4.3.1 Measurement of blood pressure
Blood pressure was measured in a sitting position using an automated, validated machine, the Omron HEM907, after a five minute rest. Results presented in this chapter are based on the mean of the second and third readings, taken at one minute intervals, in participants with valid readings, who had not eaten, drank alcohol, exercised, or smoked in the preceding 30 minutes. Full details of protocols are available in Appendix I.
Hypertension was defined as a systolic blood pressure of 140mmHg or above, or diastolic blood pressure of 90mmHg or above, or taking medication
specifically to reduce blood pressure.
4.3.2 Results
Mean systolic blood pressure was significantly higher in men (129.6mmHg) than women (124.7mmHg) and significantly higher in older adults aged 65 years and over than in younger adults aged 19 to 64 years. The difference with age was greater in women (138.6mmHg in those aged 65 years and over, 119.7mmHg in those aged 19 to 64 years) than in men (136.2mmHg and 128.0mmHg respectively). Mean diastolic blood pressure, however, varied neither by age group nor by sex.
Hypertension was significantly more common in older men and women than in younger adults. Among adults aged 19 to 64 years, 6% were on treatment for hypertension (i.e. controlled or uncontrolled hypertension), compared with 39% of older adults (40% of men and 38% of women aged 65 years and over). Untreated high blood pressure was twice as common in older adults (25% of men and 23% of women aged 65 years and over, compared with 14%
of men and 10% of women aged 19 to 64 years).
(Table 4.2)
4.3.3 Comparisons with other surveys3
Mean systolic and diastolic blood pressure among participants in NDNS were very similar to the data from Scotland (SHeS 2008/09)1, 11 and England (HSE 2009).2 For example, mean systolic blood pressure in men was 129.6mmHg in NDNS, 130.3mmHg in SHeS 2008/091,11 and 129.9mmHg in HSE 20092; in women it was 124.7mmHg in NDNS, 125.5mmHg in SHeS 20091 and
123.5mmHg in HSE 2009.2 Mean diastolic blood pressure in men was
74.2mmHg in NDNS, 73.8 mmHg in SHeS 2008/091,11 and 73.7mmHg in HSE 2009;2 the equivalent figures for women in the same age groups were
73.5mmHg in NDNS, 73.9mmHg in SHeS 2008/091,11 and 72.1mmHg in HSE 2009.2
Twenty-nine per cent of men in NDNS, 32% of men in HSE 20092 and 35% of men in SHeS 2008/091,11 had survey-defined hypertension (raised blood pressure and/or on medication for hypertension). In women, prevalence was 28% in NDNS, 27% in HSE 20092 and 30% in SHeS 2008/09.1,11
References and endnotes
1 Bromley C, Given L, Ormston R. (eds.) The Scottish Health Survey 2009. Edinburgh:
Scottish Executive, 2010.
2 Craig R, Hirani V. (eds). Health Survey for England 2009. Leeds: Information Centre, 2010
3 Comparisons of NDNS with health surveys in Wales and Northern Ireland could not be made due to the data not being comparable or available. The Welsh Health Survey uses self-report, not measured weight and height for adults. The most recent Northern Ireland survey (carried out in 2005/06) did not include a measurement module.
4 All fieldworkers were trained to carefully observe the standard measurement protocols. Each measurement was taken twice. Where the discrepancy between the measurements was at or above a given value (height ≥ 0.5cm, weight ≥ 0.2kg, waist and hip circumferences ≥ 3cm), a third measurement was taken. The mean of the two closest measurements was used. If only one measurement was available, it was excluded from the analysis.
5 World Health Organisation body mass index (BMI) classification. [On-line]
www.who.int/bmi/index.jsp?introPage=intro_3.html (accessed 05/10/2010).
6 National Institute of Health and Clinical Excellence. Obesity: the prevention, identification, assessment and management of overweight and obesity in adults and children. [On-line]
www.nice.org.uk/guidance/index.jsp?action=download&o=38295. page 221 (accessed 05/10/2010).
7 Royal College of Paediatrics and Child Health / World Health Organisation. The UK_WHO Growth Charts: Early Years. London: RCPCH, 2009. www.rcpch.ac.uk/Research/UK-WHO-Growth-Charts (accessed 05/10/2010).
8 The new UK-WHO 0-4 years growth charts were introduced in the UK because they represent an international standard of growth for healthy infants and young children.
Breastfed infants exhibit a healthier pattern of growth. The new charts were constructed using the WHO Growth Standards for infants aged two weeks to four years, which used data from healthy children from around the world with no known health or environmental
constraints to growth. WHO found that infants worldwide have very similar patterns of linear growth, whatever their ethnic origin. The new charts provide a description of optimal growth, describing the ideal patterns of growth for all UK children, whatever their ethnic origin and however they are fed in infancy. The WHO data is combined with birth data for gestations 23 to 42 weeks from the UK1990 growth reference, as the WHO dataset did not include preterm infants. The UK1990 reference is still to be used for children aged four years and over.
9 Cole T, Freeman JV, Preece MA. Body mass index reference curves for the UK, 1990. Arch Dis Child 1995; 73: 25-29.
10 The age at which a participant is defined as an adult is slightly different between the surveys: in the NDNS participants aged 19 years and over are classed as adults whereas for HSE and SHeS, those aged 16 years and over are defined as adults. In the results, ‘younger’
means from that minimum age up to 64 years.
11 Data collected by nurses (e.g. waist circumference, WHR and blood pressure) on the Scottish Health Surveys (SHeS) were reported for the first time in the SHeS 2009 report.The reported results were based on combined 2008 and 2009 data, to allow sufficient numbers for analysis.
12 Walters L, Kingdon A, Roberts C (eds.). Welsh Health Survey 2009.Welsh Assembly Government 2010. [On-line] new.wales.gov.uk/topics/statistics/theme/health/health-survey/results/?lang=en (accessed 25/01/2010)