Prevalence of risk factors for cardiovascular disease and their relationship with waist circumference in healthy, young adults
Authors: Houston A.M. , Barnes M.S. , Horigan G. , Wallace J.M.W. 
Published: May 2009

Background:  Cardiovascular disease (CVD) is the primary cause of mortality in the UK and body fat is one of the main modifiable risk factors which predisposes individuals to CVD (Grundy et al., 1999). However few studies have focused on assessing risk markers in younger adults. The aim of this study was to determine body composition and associated risk factors for CVD in a randomly selected sample of healthy young adults.Methods:  One hundred and twelve self‐reported healthy men and women aged 20–40 years were recruited to the study. Body composition was measured using body mass index (BMI), waist circumference (WC), waist‐to‐height ratio (WHTR), sum of skinfolds, and percentage body fat (%BF) as measured by air displacement plethysmography (using BodPod®, Life Measurement Inc., Concord, CA, USA), dual energy X‐ray absorptiometry (DXA), and bioelectrical impedance analysis (using prediction equations from Tanita®, Tanita UK Ltd, Yiewsley, Middlesex, UK). A fasting blood sample was collected and lipid profiles and high sensitivity C‐reactive protein (hs‐CRP) concentration were measured using commercially available kits (Instrumentation Laboratory) on the ILab 600 Chemistry Systems autoanalyser. Independent samples t test (or Mann–Whitney U‐test, where appropriate) and correlation analysis were performed.

Results for male and female subjects, and according to Waist Action Level 1 (WAL 1)

Anthropometry
Male (n = 55)
Female (n = 57)
<WAL 1 (n = 58)
>WAL 1 (n = 54)‡

& Biochemistry
Mean
SD
Mean
SD
Mean
SD
Mean
SD

BMI (kg m−2)
27.13
3.81
25.61
5.15
23.55
2.68
29.38***
4.29

WC (cm)
91.67
9.58
83.66***
12.27
–
–
–
–

WHTR
0.52
0.06
0.50
0.07
–
–
–

Sum of skinfolds
5.78
2.33
7.41**
3.38
5.21
2.21
8.12***
3.05

BodPod® (% BF)
22.65
8.85
32.86***
9.44
21.13
7.37
35.06***
8.26

DXA (% BF)
24.84
7.63
36.57***
8.02
25.22
7.92
36.81***
7.86

Tanita® (% BF)†
22.54
6.09
32.36***
8.26
22.12
5.85
33.55***
7.46

TC (mmol/l)
4.78
1.09
4.53
0.97
4.44
0.94
4.89*
1.08

HDL‐C (mmol L−1)
1.25
0.33
1.47***
0.3
1.45
0.35
1.26**
0.28

LDL‐C (mmol L−1)
2.98
0.93
2.59*
0.89
2.57
0.84
3.01*
0.96

LDL‐C: HDL‐C ratio
2.53
1.03
1.84***
0.74
1.87
0.76
2.51***
1.04

Triacylglycerol (mmol L−1)
1.22
0.68
1.05
0.48
0.92
0.37
1.37***
0.69

hs‐CRP (mg L−1)‡
0.90
1.66
1.20*
2.35
0.90
1.57
1.40*
2.42

Age‐adjusted correlation analysis of the relationship between mean WC and biochemical CVD risk factors

Correlation variable
R value
P value

TC (mmol L−1)
0.110
0.250

LDL‐C (mmol L−1)
0.187*
0.050

HDL‐C (mmol L−1)
−0.446***
<0.000

LDL‐C:HDL‐C ratio
0.393***
<0.000

Triacylglycerol (mmol L−1)
0.357***
<0.000

hs‐CRP (mg L−1)††
0.167
0.079

Values presented as mean and standard deviation; WAL 1: WC of 94cm (male) or 80cm (female); Mean values significantly different from the male subjects/<WAL 1 group: *P ≤ 0.05, **P ≤ 0.01, ***P ≤ 0.001.
‡There was no significant difference in age between the WAL groups;
† Male: n = 53 due to an incomplete data set.
††Median values used (Mann–Whitney U‐test).

Discussion:  The concentration of the inflammatory marker, CRP, was higher in women, an observation which has recently been reported in adolescent girls (Mackenzie et al., 2008). Greater central abdominal obesity, as assessed by higher WC, was associated with biochemical risk factors for CVD, such as lipid profile and CRP, suggesting that WC may act as a time and cost effective surrogate marker of inflammation and hyperlipidaemia in young asymptomatic adults, a finding in keeping with earlier research (Shen et al., 2006).Conclusions:  In younger healthy adults, gender, age and central obesity impact on biochemical markers established as independent risk factors for CVD, such factors can be easily assessed in the clinical setting and appear useful in identifying young adults at risk of CVD.References  Grundy, S.M., Pasternak, R., Greenland, P., Smith, S. & Fuster, V. (1999) Assessment of cardiovascular risk by use of multiple‐risk‐factor assessment equations: a statement for healthcare professionals from the American Heart Association and the American College of Cardiology. J. Am. Coll. Cardiol.34, 1348–1359.Mackenzie, K.E., Wiltshire, E.J., Peña, A.S., Gent, R., Hirte, C., Piotto, L. & Couper, J.J. (2008) Hs‐CRP is associated with weight, BMI, and female sex but not with endothelial function in children with type 1 diabetes. Pediatr. Diabetes10, 44–51.Shen, W., Punyanitya, M., Chen, J., Gallagher, D., Albu, J., Pi‐Sunyer, X., Lewis, C.E., Grunfeld, C., Heshka, S. & Heymsfield, S.B. (2006) Waist circumference correlates with metabolic syndrome indicators better than percentage fat. Obesity14, 727–736.