Congenital heart diseases are those diseases that occur at birth from abnormalities of cardiac structure due to aberration in development. (1) The rising trend in the prevalence of congenital heart disease is variable. Denise et al. (2) in a meta-analysis noted an increase in world prevalence from 0.6 per 1,000 live births in 1930 to 9.1 per 1,000 live births presently. Chinawa et al., (3) in Enugu, Nigeria, noted a prevalence of 0.22% among 31,795 children that attended children outpatient clinics. Congenital heart disease has been a serious challenge to affected families and relations. This is as a result of a complex interplay between high medical bills, cost of surgery, and heavy nutritional burden (4). There is a high burden of frequent hospital admission, poor surgical outcome, and death caused by malnutrition in children with congenital heart disease (4).

Adequate nutrition enhances physical and mental development, speeds academic performance, and helps in general well-being of a child from birth to adulthood. Infants and children are more likely to suffer from chronic malnutrition than older children (5, 6). Malnutrition afflicts children with congenital heart disease irrespective of presence or absence of cyanosis (7). Inadequate intake, increase basal metabolic rate from haemodynamic changes arising from the cardiac defects, and hypoxia have all been attributed to the cause of malnutrition in these children (8).

Malnutrition causes loss of body mass in children with congenital heart disease, especially the heart muscles. This in a long run will impair myocardial and pulmonary function of the heart. It also affects both cellular and humoral immunity with the consequent increase in risk of recurrent infection (9).

There are many studies on the assessment of nutritional status in children with congenital heart disease but studies that compare nutritional status with children without congenital heart disease are very few. This comparative study will help to know the actual burden of malnutrition in these children when compared to controls.

Some studies on nutritional status of children have been documented. For instance, findings on malnutrition in children with congenital heart disease in a particular study did not compare their findings with control (10). Furthermore, in the said study, malnutrition was classified as mild to severe without addressing the Z scores or BMI of these children, which will help to know whether nutritional derangement is of acute or chronic onset.

The present study is therefore aimed at determining the nutritional status of children with congenital heart disease and to compare them with those without congenital heart disease. It also aims to determine different degrees of malnutrition in subjects and controls.

Five hundred and forty-seven children participated in the study, comprising 291 children with various congenital heart diseases (subjects) and 256 children without congenital heart disease (controls). Table 1 depicts the gender distribution of the subjects and controls. The gender of subjects and controls were matched (χ2 = 0.57, p = 0.45). The mean age in months of the subjects, 43.1 (51.7), and the controls, 49.5 (36.1), were matched as well (Student t-test = −1.7, p = 0.1). Among the subjects, 78.4% (228/291) had acyanotic congenital heart disease and 21.6% (63/291) had cyanotic congenital heart disease.

The age group distribution of the subjects and controls is shown in Table 2, indicating that the majority of the participants are under the age of five years and the distribution was similar in both groups (χ2 = 4.9, p = 0.1).

Under five (1 to 60 months), child (61 to 120 months), adolescent (121 to 216 months).

The mean weight, height/length, and body mass index (BMI) of subjects were significantly lower than that of the controls as illustrated in Table 3.

Among the subjects, the mean weight was comparable between those with cyanotic, 13.3 (8.1) kg, and acyanotic, 13.8 (14.1) kg, congenital heart disease (t = 0.3, p = 0.8). The BMI was also comparable between those with cyanotic congenital heart disease, 14.1 (2.5) kg/m², and those with acyanotic congenital heart defects, 14.8 (3.4) kg/m² (t = 1.7, p = 0.1). On the other hand, those with cyanotic defect had higher mean height/length than those with acyanotic defects, 96.9 (27.1) vs. 86.9 (32.0) cm (t = −2.3, p = 0.02).

Among the subjects, the mean weight was significantly higher in females, 15.4 (14.2) kg, than in males, 12.2 (11.7) kg, {t = −2.1, p = 0.04}. The mean height/length in females, 93.5 (32.5) cm, was also significantly higher than that of males, 85.0 (29.7) cm, {t = −2.3, p = 0.02}. However, the mean BMI in females, 15.9 (2.7) kg/m², was comparable to that of the males, 16.0 (2.3) kg/m², {t = 0.1, 0.9}.

The nutritional status of subjects and controls is as in Tables 4, 5. The body mass index-for-age z-score (BAZ) and height/length-for-age z-score (HAZ) were calculated for both subjects and controls to determine their nutritional status. It was observed that 38.5% (112/291) of the subjects were wasted (BAZ < −2SD) compared to 6.25% (16/256) of the controls and the difference was statistically significant (χ2 = 81.2, p < 0.001). Stunting (height/length-for-age z-score < −2SD) was also observed in a greater proportion of subjects than controls as 37.8% (107/291) of subjects were stunted compared with 7.0% (18/256) of the controls (χ2 = 69.9, p < 0.001).

The under-five subjects had more cases of malnutrition than the controls of same age group as illustrated in Table 6. Whereas 42.9% (96/224) of the under-five subjects were wasted, only 6.2% (12/192) of the controls were wasted. On the other hand, 4.2% (8/192) of the under-five controls were obese compared to 0.9% (2/224) of the subjects of similar age group.

Also, 16.5% (37/224) of subjects compared with 4.7% (9/192) of controls of the under-five age group were stunted whereas 26.3% and 3.6% had severe stunting (HAZ, −3SD) respectively as shown in Table 7. The difference in proportion of under-five children with stunting between the subjects and control was statistically significant (χ2 = 15.7, p = 0.003).

Among the subjects, those with cyanotic congenital heart disease had relatively higher cases of malnutrition than those with acyanotic disease. A total of 42.8% (27/63) of those cyanotic disease were wasted compared with 37.3% (85/228) of those with acyanotic disease. However, the difference was not statistically significant (χ2 = 2.54, p = 0.5).

This study showed that 38.5% of children with congenital heart disease were wasted compared to 6.25% of the controls, while stunting was also observed in 37.8% compared with 7.0% seen in children without congenital heart disease. This finding was lower when compared with that of Basheir et al. (12) who noted a high prevalence of 84%. Higher prevalence has also been documented in several studies compared to ours. For instance, rates of 85%, 59%, and 90.4% have been reported in Turkey, (13) South India, (14) and Nigeria, (15) respectively. Methodology and large sample size could explain the lower prevalence seen in this study.

However, Batte et al. (16) also noted similar prevalence of wasting and stunting as 31.5 and 45.4% respectively, while Okoroma et al. (15) noted wasting and stunting as 41.1, 28.8, 2.6, and 3.9% in subjects and controls. There is a decreasing trend of malnutrition in children with congenital heart disease when compared to what was obtained some years ago. Advanced knowledge in nutritional rehabilitation, increased awareness, and frequency in the diagnosis of congenital heart disease could explain this declining trend.

Children with cyanotic congenital heart disease present with more episodes of wasting than their acyanotic counterpart. This study is also in keeping with that of Basheir et al. (12) who noted that stunting was associated with acyanotic CHD, and wasting with cyanotic CHD. Several studies have reported different findings in this regard. For instance, Okoromah and his colleagues (15) reported wasting more in left to right shunt lesions. Chronic hypoxia from right to left lesion with possible prolonged pulmonary hypertension seen in the cyanotic heart disease could explain these differences.

The mean weight and height/length was significantly higher in females with congenital heart disease. Female children have small body surface area at birth compared to their male counterparts. This issue couple with genetic variation could also explain these differences in nutritional status (17–19).

Children with congenital heart disease who are under the age of five are more prone to malnutrition than the controls of the same age group. In our setting, surgical intervention occurs very late in these children. Several studies have shown that delayed surgical correction of congenital heart disease is associated with malnutrition which is worse in children less than five years (15, 19–25). Furthermore progressive hypoxia, worsening pulmonary hypertension, and shunt reversal (harbingers of malnutrition) are common sequels that start in children less than five years old who had congenital heart disease with no intervention.

It is interesting to note from this study that children with cyanotic congenital heart defect had higher mean height/length than those with acyanotic congenital heart disease. Increased metabolic stress with resultant release of free oxygen radicals, ischemia, reperfusion, and chronic hypoxia seen commonly in children with cyanotic congenital heart disease could explain this difference (26).

Overweight and obesity were noted in 3.8 and 1.4% of children with congenital heart disease respectively, compared with 8.2 and 3.8% seen in controls. In the United States, a prevalence of over 25% of obese and overweight children were documented among children with congenital heart disease (27). This was lower in a study in Belgium where a prevalence of 7.6% was obtained. However, the study in Belgium is basically among adolescents (28).

Restrictions of physical activity and excessive nutritional rehabilitation are used for weight gain especially for infancy (29) which includes consumption of increased calories and foods with high fat and sodium content (30, 31). There had been increased risk of mal- and undernutrition in children with congenital heart disease which stems from increased metabolic rates, malabsorption, hypoxia and pulmonary hypertension (32). Most intervention therefore focused on treatment strategies that prioritize adequate growth and development. These strategies include increased caloric intake not considering the type and severity of the cardiac lesion (21, 33).

We used body mass index-for-age z-score (BAZ) and height/length-for-age z-score (HAZ) in assessing nutritional status in this study. Height/length-for-age z-score (HAZ) is used in the diagnosis of stunting while the BMI is used for overweight and obesity (22, 23).

It is important to stress here that there had been lots of screening tools for nutritional status including the use of BMI (27, 28). BMI is very useful for population studies and epidemiological studies (34–36).

Children with congenital heart disease present with varying degrees of malnutrition that is worse compared with children without congenital heart disease. The impact of malnutrition is worse among children under the age of five. Wasting is more prevalent in children with cyanotic heart disease compared with those with acyanotic congenital heart disease. Overweight and obesity were notable features of malnutrition in children with congenital heart disease but this is worse in children without congenital heart disease.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by UNIVERSITY OF NIGERIA. Written informed consent to participate in this study was provided by the participants' legal guardian/next of kin.

JMC contributed to the conception, while JMC, ATC, COD, BFC, and IO-A contributed in writing and proof reading of this manuscript. JMC and BFC are guarantors of the paper. All authors read and approved the final manuscript.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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