










Cardiovascular risk factors in young male adults: impact
of physical activity and parental education


Cardiovascular risk factors in young male adults: impact of
physical activity and parental education

Serap Çuhadar1, Ayşenur Atay1,
Gülcan Sağlam1, Mehmet
Köseoğlu1, Levent Çuhadar2


1Ataturk Training and Research Hospital,
Department of Clinical
Biochemistry, Izmir, Turkey; 2Ataturk Training
and Research Hospital,
Department of General Surgery, Izmir, Turkey 



Abstract



Background: This study was conducted to assess
whether choices of
physical activity, smoking status, and parental education and income
were correlated with the health status of young adult males which are
important for preventive health policy. 

Methods: 491 18-29-year old
males from lower socioeconomical districts in Turkey participated in
this study. Information about demographic characteristics, parental
education, household income, smoking status, and physical activity was
obtained by means of a standardized questionnaire. BMI and metabolic
parameters (serum lipid profile) were assessed.


Results: Mean total cholesterol, LDL, HDL and
triglyceride levels were
in the normal range. The physically active group displayed a better
lipid profile. No relationship was found between parental education and
serum lipids. Smoking was slightly correlated with household income
(r=103, p=0.022). 

Conclusion: Young adult males who participate in
relatively high levels of physical activity are at lower CHD risk than
less active ones. The present study also showed that lower socioecnomic
status does not always correlate with higher levels of cardiovascular
risk factors. In conclusion, data supports that while family history
cannot be changed, HDL levels can be modulated by lifestyle factors as
in other populations and that with the determined benefits of
increasing physical activity and thus, HDL levels, policy reform in
schools to promote physical activity are warranted.



Keywords: educational status, lipoproteins, physical education
and training, smoking, social class, Turkey.




Research



Introduction



Mortality rates from coronary heart disease (CHD), which rose during
the twentieth century, started declining in most industrialized regions
such as in United States and in Europe during the 1960s because of
preventive studies.1-4 



In Turkey,5 the prevalence of CHD is higher than
in the US and Europe.
As a developing country, rapid lifestyle changes (fast food, obesity,
physical inactivity), lower socieconomic status (SES), and high smoking
prevalence are major factors in the development of CHD. Notably, Turks
have low levels of HDL (10-15 mg/dl lower than in Europeans and North
Americans)6 which appear to have genetic origin.7,8
However, though
genetically determined to a significant extent, these low HDL levels
can be modulated by lifestyle factors, as in other populations. 



Cardiovascular diseases typically occur in middle age or later, however
lifestyle behaviors are learned in early life and maintained throughout
adulthood.9,10 Physical activity levels and
dietary habits are
important health related factors that, learned in early ages, are
screening tools to identify young subjects at risk for later CHD
development.11




Reports have shown that excess weight and sedentary lifestyle among
young adults are associated with high prevalence of cardiovascular
risk.12 Low parental education has been shown to
contribute to an individual’s risk for CHD development.13



In the current study, analyses were conducted to assess whether choices
of physical activity, smoking status, and parental education and income
were correlated with the health status of young adult males, which are
important for preventive health policy.




Materials and
Methods



Study Design



This study consisted of 491 healthy male volunteers between the ages of
18 and 29.



The study group was from different regions of Turkey whose families are
mostly immigrants from lower SES parts of the country. The participants
were recruits for the police academy and were attending our hospital
for health reports. The blood samples collected during routine check up
were used for this study- no additional sample was taken. The
procedures were in accordance with the guidelines of the Helsinki
Declaration of human experimentation. All participants provided written
informed consent. The study was conducted between March and September
2011.




Blood samples were taken and information on smoking habits, physical
activity, family income, and parental education were collected by
trained staff using a self-administered questionnaire. Body mass index
(BMI) was calculated as weight (kg)/height (m2). Height was measured to
within 0.5 cm and weight to within 0.1 kg.




Measurements




After an overnight fast, blood samples were obtained to measure levels
of triglycerides (TG), total cholesterol (TC) and high-density
lipoprotein cholesterol (HDL). Serum lipids were measured on the Abbott
Architect analyzer (Abbott, Wiesbaden, Germany). Concentration of
low-density lipoprotein cholesterol (LDL-C) was calculated using the
Friedewald formula14 ([LDL-chol]=[Total chol] -
[HDL-chol] - ([TG]/2.2)
where all concentrations are given in mmol/L. Coefficients of variation
for the measured serum lipids were <3.3% (Bio-Rad laboratories,
Milano, Italy). 



Information on smoking habits, physical activity and parental education
was collected from the questionnaire. Age was calculated based on date
of birth from hospital data. The questionnaire contained the
school-based and extracurricular physical activity questions used in
the present analysis. Participants who perform moderate to vigorous
physical activity 3 or more times per week for 60 min or above, minimum
duration of 1 year, were classified as active. Remaining participants
were classified as inactive. 



In the questionnaire, current smoking status was considered to be
smokers (current or past smoking), and non-smokers (never smoked).




Household income, paternal and maternal education were used as
indicators of SES. Household income was assessed by total montly income
for a family unit living together. Income was classified into three
groups: low: ≤ $500/month, middle: $500-1,000, high: >$1,000. 



Parental education level was classified into three groups: low(1):
none + elementary school; intermediate(2): middle + high school; and
high(3): college + university.




The education levels of the study group were high school and college or
university graduate, therefore, the education level of the participants
was not considered useful for the purposes of this study.




Statistical Analyses



Risk factors were analyzed as continuous variables including age, BMI,
total cholesterol, LDL, HDL, triglycerides, and the ratio of TC to HDL.
Household income, parental education, smoking, and physical activity
were analyzed as categorical variables.



We used an independent samples t-test for
comparison of quantitative
variables. For qualitative variables, cross-tabulation and X2
tests were used. A p value <0.05
(two-tailed) was
considered significant. Normality of quantitative variables was
verified by
Kolmogorov-Smirnov test. Qualitative variables were
expressed as a percentage with a confidence interval of 95%. Pearson
and Spearman
correlation coefficients were used as appropriate. Analysis of
covariance (MANCOVA) analysis was used; age, BMI,
smoking were included
as covariates if needed. All statistical analyses were conducted with
SPSS, version 15.0 (SPSS Inc., Chicago, IL, USA).



Results



Demographic and biochemical characteristics of the participants are
presented in Table 1. 



Table 1: Demographic and biochemical characteristics of
study
participants.
	Variable	Males n=491
	Mean Age (range)*	21(18-29)
	Body mass index (SD, kg/m2)†	23.3(2.24)
	BMI >25 	25.3% 
	Mean Age (range)*	21(18-29)
	Total cholesterol (SD, mmol/L)	3.94(0.75)
	HDL-cholesterol (SD, mmol/L)	1.20(0.25)
	LDL-cholesterol (SD, mmol/L)	2.28(0.65)
	Triglycerides (range, mmol/L)*	0.87(0.23-4.09)
	Total cholesterol/HDL (SD)
cholesterol ratio
	3.5(1.0)
	Cigarette smoking (%)‡	25.1
	Physically inactive (%)	18.7
	Paternal
education (%)	
	Lower	39.3 
	Medium	22.6 
	Higher	38.1 
	Maternal
education (%)	
	 Lower	76.8 
	Medium 	14.5 
	Higher	8.8 
	Household
income (%)§	
	Lower	47.5 
	Intermediate	40.3
	Higher	12.2 


Abbreviations: HDL, high density lipoprotein; LDL, low
density
lipoprotein.


Values are means±standard deviation or percentages. Means were compared
by t-test, and percentages were analyzed by
x2-test.Statistically
significant p values are marked in bold.


* median(min-max) values for non-Gaussian distributions


† Weight (kg)/height (m)2


‡One or more cigarettes per day 

§According to Turkish Statistical Institude during September 2011 the
average Turkish net income was €790.






25.3% of the subjects (only 2 of them were obese) were overweight
(BMI>25) according to the definition by World Health
Organization.15




No associations were found between serum lipids, BMI and parental
education. 



The comparisons of physical activity and other risk factors are
presented in Table 2.



Table 2. Analysis of covariance assessing the effects of
physical
activity using lipids as dependent variables, physically activation
group as fixed factors, and age as a covariate (MANCOVA). TC/HDL-C
between groups were determined by independent samples t-test.
		Physically inactive (n=91) 	Physically active (n=399) 	F	p
	Total Cholesterol (mmol/L) 	4.07(3.92-4.22) 	3.91(3.85-3.98) 	3.57 	0.059 
	Triglyceride (mmol/L)* 	1.05(0.95-1.16)	0.89(0.84-1.08) 	9.11 	0.003**
	HDL-Cholesterol (mmol/L) 	1.10(1.05-1.15) 	1.22(1.19-1.24) 	16.13 	0.000**
	LDL-Cholesterol (mmol/L) 	2.44(2.32-2.57) 	2.24(2.18-2.30) 	7.92 	0.005**
	Total Cholesterol/HDL- Cholesterol	4.20(±1.32) 	3.27(±0.86)	44.47	0.000**


Values of lipids are means with 95%
confidence intervals in parenthesis
and the ratio data are mean ± SD.

*Data on triglycerides log10
transformed before analysis and untransformed mean values were reported
here.

**p<0.05 






In physically active adult group, a better lipid profile was determined
(Table 2).




Subjects’ smoking was not related to parental education, physical
activity, BMI or age. A statistically significant but weak correlation
was found only between with smoking and income (r=.103*, p=0.022*)
(Spearman). 



Lower HDL levels were found in subjects that cigarette smoking than
non-smoking (Table 3).




Table 3: Analysis of covariance assessing the effects of
smoking using
lipids as dependent variables, smoking as fixed factors, and age, BMI
as covariates. (MANCOVA).
		Smoking (n=123) 	Non-smoking (n=367) 	F	p
	Total Cholesterol (mmol/L) 	3.91(3.79-4.03) 	3.95(3.88-4.02) 	0.29 	0.591
	Triglyceride (mmol/L)* 	0.96(0.86-1.06)	0.90(0.86-0.96) 	0.53 	0.466
	HDL-Cholesterol (mmol/L) 	1.16(1.11-1.20) 	1.21(1.18-1.23) 	4.42 	0.036**
	LDL-Cholesterol (mmol/L) 	2.28(2.17-2.38) 	2.28(2.22-2.34) 	0.00 	0.982


** p<0.05






Discussion



We observed a better lipid profile among Turkish young adults than the
Turkish Heart Study16 within the same age group,
as we demonstrated a
higher mean concentration of HDL Cholesterol (9.2 mg/dl higher). For
these educated young adults, low parental education caused no impact on
their health status. 



Obesity and overweightness are important problems in industrialized
countries. In Greece,17 40% of male young
medical students are
overweight (BMI>25.0 kg/m2). According to a study,18
a higher
rate of obesity was established in a Turkish population relative to
European countries. In the present study, the mean BMI was calculated
as 23.3 kg/m2. 



BMI of the adults is thought to be influenced by environmental factors
related to parental education as well as by genetic factors. In
studies,19,20 BMI was found to be related to the
parental education,
however in the current study no relationship was found between. 



It is recommended that school-age youth had to participate in physical
activitiy approximately 60 min/day or more and had to reduce sedentary
behaviours to < 2 hours per day for health promotion.21
Previous
studies22-24 of the Turkish young population
suggested rather high
incidence of sedentary lifestyle and relatively low levels of
occupational physical activity. Because the participants of this study
were among the recruits for the police academy, the rate of the sports
activity was very high (81.3%) which may have introduced some selection
bias, resulting in participants being healthier. 



Cigarette smoking influences cardiovascular system because of carbon
monooxide and nicotine leading to a reduction in myocardial O2
intake.25 Although smoking is associated with
low HDL, it did not
account for the markedly low levels of HDL in Turks.6,16
Regarding
smoking status of participants, a lower rate of smoking rate was found
compared to previous studies.25-27 Paavola et al.28
considered that,
smoking status between the ages of 13-28 was not related to parental
education, occupation, or income. In this study, smoking prevalence
showed no relationship between parental education. However, others
concluded that, parental education and participants’ own education were
the strongly related factors affecting their own smoking.29




In populations at high risk for CHD caused by low HDL, the TC/HDL ratio
predicts CHD risk regardless of absolute LDL and HDL.30
In the current
study, with a population in low household income, the ratio was found
as 3.5, where it was found as 4 among Turks with similar income.6
In
contrast to a study,16 we observed that higher
salary was associated
with lower HDL. This may be due to unhealthy dietary habits as it was
showed in several studies among Turks.12,23




One limitation of this study is that the participants’ duration and
intensity of physical activity were evaluated according to their self
reports in the questionnaire. However, in randomized or nonrandomized
studies,21 supervised programs are used for the
evaluation of physical
activities, generally. Another limitation is that the recruits for the
police academy are usually more prone to physical activity compared
with the same age group. Therefore this study group does not reflect
their age-matched counterparts’ lifestyle and lipid profile, however,
we had a chance to compare the physically active young group with
sedentary ones. 



In conclusion, parental education has a lesser effect on the educated
young adults’ health statuses. Because HDL levels and physical activity
rates were higher than in previous studies, we recommend a need to
reform public health policies, especially in regards to physical
activity programs because of the determined benefits.



References



1. Ford ES, Capewell S. Proportion of the Decline in Cardiovascular
Mortality Disease due to Prevention Versus Treatment: Public Health
Versus Clinical Care. Annu Rev Public Health. 2011;32:5-22. 



2. Young F, Capewell S, Ford ES, Critchley JA. Coronary mortality
declines in the U.S. between 1980 and 2000 quantifying the
contributions from primary and secondary prevention. Am J of Prev Med.
2010;39:228-34. 



3. Unal B, Critchley JA, Capewell S. Explaining the decline in coronary
heart disease mortality in England and Wales between 1981 and 2000.
Circulation. 2004;109:1101-7. 



4. Bots ML, Grobbee DE. Decline of coronary heart disease mortality in
the Netherlands from 1978 to 1985: contribution of medical care and
changes over time in presence of major cardiovascular risk factors. J
Cardiovasc Risk. 1996;3:271-6. 



5. Onat A. Risk factors and cardiovascular disease in Turkey.
Atherosclerosis 2001;156:1-10. 



6. Mahley RW, Can S, Ozbayrakçi S, et al.
Modulation of high-density
lipoproteins in a population in Istanbul, Turkey, with low levels of
high-density lipoproteins. Am J Cardiol 2005;96:547-55. 



7. Lüttmann S, von Eckardstein A, Wei W, et al.
Electrophoretic
screening for genetic variation in apolipoprotein C-III: identification
of a novel apoC-III variant, apoC-III(Asp45➝Asn), in a Turkish patient.
J Lipid Res. 1994;35: 1431-40. 



8. Bersot TP, Vega GL, Grundy SM, et al. Elevated
hepatic lipase
activity and low levels of high density lipoprotein in a
normotriglyceridemic, nonobese Turkish population. J Lipid Res.
1999;40:432-8. 



9. Nicklas TA, Webber LS, Berenson GS. Studies of consistency of
dietary intake during the first four years of life in a prospective
analysis: Bogalusa Heart Study. J Am Coll Nutr. 1991;10 :234-41. 



10. Eriksson JG, Forsén T, Tuomilehto J, et al.
Early growth and
coronary heart disease in later life: longitudinal study. BMJ.
2001;322:949-53. 



11. Farajian P, Renti E, Manios Y. Obesity indices in relation to
cardiovascular disease risk factors among young adult female students.
Br J Nutr 2008;9:918-924.




12. Mahley RW, Arslan P, Pekcan G, et al. Plasma
lipids in Turkish
children: impact of puberty, socioeconomic status, and nutrition on
plasma cholesterol and HDL. J Lipid Res. 2001;42:1996-2006. 



13. Leino M, Raitakari OT, Porkka KV, et al.
Associations of education
with cardiovascular risk factors in young adults: the Cardiovascular
risk in young Finns study. Int J Epidemiol. 1999;28:667-75. 



14. Friedewald W, Levy R, Fredrickson D. Estimation of the
concentration of low-density lipoprotein cholesterol in plasma, without
use of the preparative ultracentrifuge. Clin Chem. 1972;18: 499-502. 



15. Obesity: preventing and managing the global epidemic. Report of a
WHO consultion on obesity, Geneva, World Health Organization,2003. 



16. Mahley RW, Palaoğlu KE, Atak Z, et al. Turkish
Heart Study: Lipids,
lipoproteins, and apolipoproteins. J Lipid Res. 1995;36:839-59.




17. Bertsias G, Mammas I, Linardakis M, Kafatos A. Overweight and
obesity in relation to cardiovascular disease risk factors among
medical students in Crete, Greece. BMC Public Health 2003;3:3.




18. Iseri A, Arslan N. Obesity in adults in Turkey: age and regional
effects. Eur J Public Health 2009;19:91-4. 



19. Burke GL, Jacobs DR Jr, Sprafka JM, et al.
Obesity and overweight
in young adults: the CARDIA study. Prev Med 1990;19:476-88.




20. Gonzalez A, Boyle MH, Georgiades K, et al.
Childhood and family
influences on body mass index in early adulthood: findings from the
Ontario Child Health Study. BMC Public Health. 2012; 12: 755. 



21. Strong WB, Malina RM, Blimkie CJ, et al.
Evidence based physical
activity for school-age youth. J Pediatr 2005; 146(6):732-7. 



22. Uçar B, Kiliç Z, Colak O, et al. Coronary risk
factors in Turkish
schoolchildren: Randomized cross-sectional study. Pediatr Int
2000;42:259-67. 



23. Manios Y, Dimitriou M, Moschonis G, et al.
Cardiovascular disease
risk factors among children of different socioeconomic status in
Istanbul, Turkey: directions for public health and nutrition policy.
Lipids Health Dis 2004;3:11. 



24. Daskapan A, Tuzun EH, Eker H. Perceived barriers to physical
activity in university students. J Sports Sci Med 2006;5:615-20.
Available from: http://www.jssm.org.




25. Yıldız L, Kılıç H. The clinical and biochemical effects of
cigarette smoking. J Med Sci 2000;20:306-12.




26. van Oort FV, van der Ende J, Crijnen AA, et al.
Determinants of
daily smoking in Turkish young adults in the Netherlands. BMC Pub
Health. 2006;6:294. 



27. Ertas N. Factors associated with stages of cigarette smoking among
Turkish youth. Eur J Public Health 2006;17:155-61. 



28. Paavola M, Vartiainen E, Haukkala A. Smoking from adolescence to
adulthood: the effects of parental and own socioeconomic status. Eur J
Public Health 2004;14:417-21. 



29. Kestila L, Koskinen S, Martelin T, Rahkonen O. Influence of
parental education, childhood adversities, and current living
conditions on daily smoking in early adulthood. Eur J Public Health
2006;16(6):617-626. 



30. Bersot TP, Pépin GM, Mahley RW. Risk determination of dyslipidemia
in populations characterized by low levels of high-density lipoprotein
cholesterol. Am Heart J. 2003;146:1052-9.
