Brief Reports

Indian Pediatrics 2002; 39:168-172  

Lipid Profile in Children Aged 5 to 15 years with Parental History of Ischemic Heart Disease, Hypertension and Diabetes Mellitus

From the Department of Pediatrics, Government Medical College, Amritsar, Punjab.

Correspondence to: Dr. N.K. Anand, HM-34, Anand Avenue, Amritsar 143 001, Punjab, India.

Manuscript received: October 30, 2000;
Initial review completed: December 5, 2000;
Revision accepted: June 28, 2001.

The incidence of coronary artery disease (CAD) at an early age has shown a rising trend and a correlation of hyperlipidemia with early CAD in young individuals has been well established(1). CAD when occurs at an early age generally follows a serious course. Premature and extensive atherosclerosis leads to higher mortality in young Asians than the other ethnic groups. The incidence of CAD is 3-4 times higher in young Indians than their counterparts in the West(2).

It has been found that the values of various lipid fractions are higher in children in whom parental history of ischemic heart disease (IHD) is positive and out of which serum cholesterol is the most important lipid fraction(3). Prevalence of hypertension (HT) in young patients with CAD in India varies from 12-32% and with diabetes mellitus (DM) varies from 5-18%(4).

It appears that atherosclerosis develops at an early age and comparatively at lower levels of serum lipids in individuals with parental history of IHD, HT and DM. This study was therefore undertaken to determine the lipid profile in children with parental history of IHD, HT and DM and correlate the lipid profile of these children with that of a control group of children.

The present study was conducted in the Pediatrics Department of Government Medical College, Amritsar from January 1997 to July 1998. The study sample included 100 children in the age group of 5-15 years. None of the children was obese as per body mass index criteria. These children were divided into 4 groups of 25 cases each with parental history of IHD, HT, DM and a control group. The parents of the control group did not suffer from any of the diseases mentioned in the study. The parents were selected from the Medical OPD of Guru Nanak Dev Hospital, Amritsar (attached to Government Medical College, Amritsar). The parents (either father or mother) were suffering from the disease entities for more than 5 years but none of them suffered from more than one disease entity. When the number of children in a particular group was 25, that group was considered complete. All the children were physically examined and lipid profile of these children and their diseased parents was done. Hyperlipidemia due to different secondary causes like renal, endocrinal, liver disorder, storage diseases was excluded. Total serum cholesterol was estimated by Zlatkis method modified by Zak(5). HDL-C was estimated by Burstein et al. method(6). For serum trigly-cerides, colorimetric method using Hantzsch Reaction (7) was used. LDL-C was calculated by Freide Wald equation(8), i.e., LDL-C = Total cholesterol - HDLC + Triglycerides.

After doing the lipid profile of these cases and the parents, values of each group were compared with the controls.

These 100 children were studied under two age groups of 5-9 years and 10-15 years of age. The number of children in the age group of 5-9 years and 10-15 years were 43 and 57, respectively. Two-thirds of the children were males and one third were females.

Mean total serum cholesterol was signi-ficantly higher (p <0.001) in the diseased parents as compared to the controls as well as in the children with parental history of IHD, HT and DM as compared to the controls. The mean serum HDL-C was significantly higher (p < 0,001) in children with parental history of these diseases than controls but was significantly low (p <0.001) in the diseased parents than controls. There was no signi-ficant difference (p >0.05) in the mean ratio of total serum cholesterol and HDL-C among the children with parental history of IHD, HT, DM and control group of children but this ratio was significantly higher (p <0.001) in diseased parents. Mean LDL-C was signi-ficantly higher in the children (p <0.05) with parental history of these diseases as well as in the diseased parents (p <0.001) than the controls. There was no significant difference (p >0.05) in the serum triglyceride levels among the children with parental history of these diseases and control group of children. Also there was no significant difference (p >0.05) in serum triglyceride levels among fathers suffering from DM as compared to controls, although it was significantly higher (p <0.001) in all the diseased mothers as well as in the fathers suffering from IHD and HT as depicted in Table I.

Mean total serum cholesterol, HDL-C and LDL-C were significantly higher (p <0.05) in the children of both the age groups with parental history of IHD, HT and DM as compared to the controls. However, data of 11 children between 14-15 years of age showed that there was no significant difference (p >0.05) in the serum HDL-C levels as compared to the control group of children. No statistically significant difference (p >0.05) was observed in the mean serum triglyceride levels in the children with parental history of IHD, HT, DM and control group of children in both the age groups (Table II).

There was no statistically significant sex difference (p >0.05) in the value of any lipid fraction in the children with parental history of IHD, HT and DM as compared to the controls.

Table I__Lipid Profile in Various Study Groups

* p >0.05 – Not significant, ** p <0.05 – Significant *** p <0.001 – Highly significant, # The sample size for each group is 25.

Table II__Distribution and Lipid Profile of Chidren of Various Study Groups

* p >0.05 – Not significant, ** p <0.05 – Significant, *** p <0.001 – Highly significant.

Arterial pathology studies have shown that fatty streaks are present in the aorta of children as young as 2-3 years of age and by the age of 20 years, these lesions become significantly raised leading to the development of pre-mature atherosclerosis in adulthood and so the premature clinical disease. Such children should be identified in early life in order to reduce the associated risks of premature CAD.

Various risk factors are associated with the development of premature atherosclerosis and CAD in high risk children. Higher serum levels of cholesterol, triglycerides and LDL-C are some of the important predisposing factors in such cases. It has been found that hypercholesterolemia is more in children of parents with documented hypercholestero-lemia and symptomatic CAD. In children total serum cholesterol <170 mg/dl is considered optimal, 170-199 mg/dl as borderline and >200 mg/dl is a risk to the development of atherosclerosis(9).

The value of different fractions of lipid profile in our study among high risk children having parental history of IHD, HT and DM correlates well with the previous studies(10). As the total serum cholesterol/HDL-C ratio goes on rising, it predisposes to early CAD(11). This ratio in present study of high risk children was much higher(2.53 to 2.80) than the ratio given by earlier workers(12). Although HDL-C levels were also increased in younger age groups of <14 years but beyond this age HDL-C started decreasing and Cholesterol/HDL-C ratio started rising, thus increasing the risk of CAD in younger adults.

In addition to hyperlipidemia, parental history of IHD, HT and DM are other impor-tant factors for development of premature atherosclerosis. It has been shown that each risk factor separately increases the risk of CAD five to ten times when compared with persons having no risk factors.

It is concluded that parental history of IHD, HT and DM affect the lipid profile of children. Thus periodic evaluation of lipid profile of such children may be of vital importance to anticipate the risks involved and to initiate measures to lower such risks.

Contributors: NKA conceived the study and drafted the manuscript and he will act as the guarantor. PS and DS collected the data, analyzed it and interpreted it and helped in drafting.

Funding: None.

Competing interests: None stated.

 

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