High cholesterol: Scottish data

Prevalence

Table 1 shows the mean total cholesterol level in the Scottish population, as estimated in the Scottish Health Survey.

Table 1: Mean total cholesterol (mmol/l),  by age and sex, 1995, 1998 and 2003

	Men			Women
Age	1995	1998	2003	1995	1998	2003
16 to 24 years	4.4	4.3	4.3	4.7	4.4	4.5
25 to 34 years	5.4	5.1	5.2	5.1	4.9	5.0
35 to 44 years	5.9	5.6	5.6	5.4	5.1	5.4
45 to 54 years	6.1	5.9	5.9	6.1	5.8	5.9
55 to 64 years	6.1	5.8	5.7	6.5	6.1	6.3
65 to 74 years	n/a	5.6	5.5	n/a	6.3	6.1
75+ years	n/a	n/a	5.1	n/a	n/a	6.0
16 to 64 years	5.6	5.4	5.4	5.6	5.3	5.5

Source: Scottish Health Survey 2003, Volume 1: Cardiovascular Disease, Table 1.20.

This shows that the average total cholesterol level is below the limit for 'raised cholesterol' (6.5 mmol/l), but is still fairly high compared to the 'optimum' (3.8 mmol/l). The following table shows that a sizeable proportion of individuals within the population do have a raised total cholesterol level:

Table 2: Percentage of the population with a raised cholesterol level (over 6.5 mmol/l),  by age and sex, 1995 and 1998

	Men		Women
Age	1995	1998	1995	1998
16 to 24 years	1.3%	2.0%	4.3%	2.9%
25 to 34 years	14.9%	6.7%	8.1%	4.3%
35 to 44 years	30.1%	21.9%	14.9%	6.9%
45 to 54 years	34.9%	27.3%	31.7%	23.5%
55 to 64 years	32.2%	23.9%	50.8%	38.6%
65 to 74 years	n/a	18.1%	n/a	43.3%
16 to 64 years	22.5%	16.7%	21.3%	14.7%

Source: Scottish Health Survey 1998, Volume 1, Chapter 2 (Table 2.19 for ages 16-64, and Table 2.18 for ages 65-74).

The data show that overall nearly 20% of the population aged 16-64 years have a raised cholesterol level (around 515,000 - 721,000 people in this age band). In general, the percentage with a raised cholesterol level increases with age - especially in women. There appears to be a reduction in the prevalence of raised cholesterol levels between 1995 and 1998, but this could be due to random variation or changes in the way the test is carried out.

Data for 2003 are not presented in Table 2, as the 2003 Scottish Health Survey uses 5.0 rather than 6.5 mmol/l as the cut-off point for 'raised cholesterol'.  This more stringent cut-off point gives an estimate of the prevalence of raised cholesterol to be about 63% of the population aged 16-64 years.

Primary care activity

The most up-to-date data on patients seen in primary care in Scotland (2005/06) estimates that 1.3% of the total population (over 71,000) were seen by a member of the general practice team over the previous year to deal with a high cholesterol level (see first worksheet in High cholesterol PTI Aug07  (34Kb)). This is far fewer than the 515,000 - 721,000 people in the 16-64 year age band alone who are estimated to have high cholesterol. 

The above Excel file includes three worksheets with detailed practice team information estimates for high cholesterol: patients by gender and age; patients by gender and deprivation category; and contacts per patient by gender and deprivation category.

Mortality estimates

The World Health Organization has estimated that worldwide about 8% of all deaths are attributable to a 'non-optimal' cholesterol level (mean cholesterol over 3.8 mmol/l) (Lawes et al, 2004). Applying this percentage to Scotland would give an estimate of around 4,500 deaths per year attributable to raised cholesterol levels.