Nutritional status of children with heart disease attending outpatient clinic at a tertiary health center in Lagos

Abstract

BACKGROUND

Malnutrition is a well-recognized complication of pediatric heart disease, resulting from increased metabolic demands, feeding difficulties, and recurrent illness. It contributes significantly to poor growth, impaired immunity, increased susceptibility to infections, and adverse clinical outcomes, including higher perioperative risk. Assessing nutritional status in this population is therefore essential for optimizing management and long-term prognosis.

AIM

To assess the nutritional status of children with heart disease attending an outpatient clinic in Lagos and compare it with that of healthy controls.

METHODS

This hospital-based cross-sectional study was conducted from February 2024 to August 2024 at Lagos State University Teaching Hospital. Seventy children aged 7-16 years with diagnosed heart disease were recruited and matched by age, sex, and socioeconomic status with 70 apparently healthy controls. Nutritional assessment included weight, height, and body mass index with indices expressed as World Health Organization Z-scores. Data were analyzed using SPSS version 24, with P < 0.05 considered statistically significant.

RESULTS

The mean age of participants was 10.5 ± 2.7 years, with a slight female predominance. Children with heart disease had significantly lower weight-for-age, height-for-age, and body mass index-for-age Z-scores compared to controls (P < 0.05). Overall, 48.6% of children with heart disease were malnourished vs 4.3% of controls. Within the heart disease group, poorer nutritional status appeared more common among children with complex or uncorrected lesions and those with frequent hospitalizations.

CONCLUSION

Children with heart disease had significantly poorer nutritional indices than their healthy peers, underscoring the need for routine nutritional assessment and targeted interventions. Early corrective surgery and proactive nutritional support may improve outcomes in this vulnerable group.

Key Words: Malnutrition; Heart disease; Children; Lagos; Nutritional status

Core Tip: Malnutrition harms growth, immunity, and outcomes; assessing nutrition is vital in pediatric heart disease. Malnutrition significantly contributes to poor growth, impaired immunity, increased susceptibility to infections, and adverse clinical outcomes, including a higher perioperative risk. Assessing nutritional status is essential for optimizing management and long-term prognosis in children with congenital and acquired heart diseases.

INTRODUCTION

Heart disease in children encompasses a spectrum of conditions, both congenital and acquired, that affect the structure and function of the heart. These conditions pose significant clinical and public health challenges, particularly in low- and middle-income countries where late diagnosis and limited access to surgical interventions remain prevalent. Children living with heart disease are at increased risk of complications, including congestive heart failure, recurrent respiratory tract infections, growth failure, impaired nutritional status, and psychosocial difficulties[1-3].

Nutritional status plays a critical role in the overall health and prognosis of these children. Anthropometric measurements such as weight, height, body mass index, and mid-upper arm circumference remain essential tools for assessing growth and nutritional adequacy, particularly in the context of chronic illness[4]. These parameters help identify undernutrition, which is commonly reported among children with congenital and acquired heart diseases[5].

Previous studies have documented a high prevalence of growth impairment in this population. For example, Rubia and Kher[6] in a 2018 case-control study in India demonstrated a significantly higher prevalence of underweight and stunting among children with unoperated congenital heart disease (CHD) compared with healthy controls. Similarly, Okoromah et al[5] in southwestern Nigeria reported malnutrition in 90.4% of children with CHD compared to 21.1% of controls. However, many studies have focused primarily on unoperated congenital lesions, with limited data comparing children who have undergone surgical correction or those with acquired heart disease. This gap limits a comprehensive understanding of the nutritional burden across the full spectrum of pediatric cardiac conditions.

Poor nutritional status in children with heart disease can exacerbate the severity of their illness, leading to impaired growth and development, compromised immunity, increased susceptibility to infections, and adverse perioperative outcomes[7]. Not all children with cardiac disease experience similar degrees of nutritional compromise; factors such as the type and severity of the lesion, frequency of hospitalizations, presence of comorbidities, and number of surgical interventions significantly influence nutritional outcomes.

Despite the recognized importance of nutrition in the management of pediatric heart disease, data from Nigeria remain scarce, particularly studies encompassing both congenital and acquired conditions. This study, therefore, aims to describe the nutritional status of children with heart disease attending an outpatient clinic in Lagos and to identify associated risk factors. Findings from this research will provide baseline evidence to inform clinical practice and guide targeted interventions to improve health outcomes for this vulnerable population.

Research questions

What is the nutritional status of children with heart disease attending the outpatient clinic at the Lagos State University Teaching Hospital, Lagos? Is there a significant difference in the nutritional status of children with heart disease attending the outpatient clinic at the Lagos State University Teaching Hospital, Lagos, compared to their apparently healthy matched controls? Are there risk factors for malnutrition among children with heart disease attending the outpatient clinic at the Lagos State University Teaching Hospital, Lagos?

Research hypothesis

Null hypothesis: There is no statistically significant difference in the nutritional status of children with heart disease attending the outpatient clinic of the Lagos State University Teaching Hospital, Lagos, compared with apparently healthy controls.

Alternate hypothesis: There is a statistically significant difference in the nutritional status of children with heart disease attending the outpatient clinic of the Lagos State University Teaching Hospital, Lagos, compared with apparently healthy controls.

MATERIALS AND METHODS

This cross-sectional correlation study was a sub-study of a large study conducted over seven months (February 2024 to August 2024) at the Paediatric Cardiology and General Outpatient Clinics of the Lagos State University Teaching Hospital, Ikeja, Lagos. The study population included children aged 7-16 years with previously diagnosed heart disease attending the cardiology clinic, and age-, sex-, and socio-economic status-matched healthy controls from the general paediatric outpatient clinic. Study subjects were assigned to socioeconomic classes based on the level of education and occupation of their parents, as stated by Ibadin and Akpede[8]. Occupation and educational levels were graded on a scale of 1 to 6. One is the highest score, and six is the lowest score obtainable. The total score was divided by 4 if both parents are available, or by 2 if only one parent or caregiver is available. The derived value was approximated to the nearest whole number to give the social class of the child. The resultant score range of 1-6 is classified into the following socioeconomic classes: Upper class (scores 1 and 2), middle class (scores 3 and 4), and lower class (scores 5 and 6). Children with other chronic illnesses or those on antidepressant/antipsychotic medications were excluded. A total of 140 participants were recruited, 70 with heart disease and 70 healthy controls.

Ethical approval was obtained from the Health Research and Ethics Committee of Lagos State University Teaching Hospital. Written informed consent and child assent were obtained before data collection. Data were collected using an interviewer-administered proforma, and the study instrument/tools included the Omron HD 283 electronic weighing scale and Stadiometer (Seca 213^®).

Statistical analysis

Data were analyzed using SPSS version 24. Categorical variables were presented as n (%); continuous variables (anthropometry) as means ± SD. Group comparisons used t-tests as appropriate. Logistic regression identified factors associated with poor nutritional indices. P < 0.05 was considered statistically significant.

RESULTS

A total of 140 children aged between 7 years and 16 years, with a male: Female ratio of 1:1.12, were recruited from February 2024 to August 2024 at the Lagos State University Teaching Hospital, Lagos State, Nigeria. The predominant age group was 10 years to 12 years. The mean age for participants with heart disease and the comparison group was 10.47 ± 2.7 years and 10.52 ± 2.7 years, respectively (P = 0.995). Parents or caregivers were aged 25-62 years. Most participants in this study had a middle socio-economic status; however, the social distribution did not differ significantly between those with heart disease and the controls (P = 0.575). The distribution of participants by ethnicity in those with heart disease and the control group was comparable (P = 0.711), with almost 7 out of 10 participants being of the Yoruba ethnicity, as shown in Table 1.

Table 1 Socio-demographic characteristics of participants, n (%).

Socio-demographics	Heart disease (n = 70)	Controls (n = 70)	Total	χ2	P value
Age group (years)
7-9	25 (35.7)	25 (35.7)	50 (35.7)	0.000	1.000
10-12	29 (41.4)	29 (41.4)	58 (41.4)
13-16	16 (22.9)	16 (22.9)	32 (22.9)
mean ± SD	10.47 ± 2.7	10.52 ± 2.7		0.019	0.995
Sex
Female	37 (52.9)	37 (52.9)	74 (52.9)	0.000	1.000
Male	33 (47.1)	33 (47.1)	66 (47.1)
Ethnic group
Yoruba	51 (72.9)	45 (64.3)	96 (68.6)	1.375	0.711
Igbo	11 (15.7)	13 (18.6)	24 (17.1)
Hausa	5 (7.1)	7 (10.0)	12 (8.6)
Others	3 (4.3)	5 (7.1)	8 (5.7)
Social economic status
Lower	21 (20.0)	16 (22.9)	37 (26.4)	1.108	0.575
Middle	44 (62.9)	47 (67.1)	91 (65.0)
Upper	5 (7.1)	7 (10.0)	12 (8.6)
Living with parent
Yes	63 (90.0)	60 (85.7)	123 (87.9)	0.603	0.438
No	7 (10.0)	10 (14.3)	17 (12.1)
Previous abuse
Yes	8 (11.4)	7 (10.0)	15 (10.7)	0.075	0.785
No	62 (88.6)	63 (90.0)	125 (89.3)

Clinical profile of participants with heart disease

Figure 1 shows the broad classification of heart disease among participants. The majority (80.7%) of them have CHD, out of which more than half have acyanotic CHD. Less than a fifth of the participants with heart disease were acquired heart disease.

Figure 1 Classification of heart disease.

Anthropometry measurements of study participants

Table 2 shows the anthropometry of participants. The mean weight-for-age, height-for-age, and body mass index-for-age of children with heart disease were significantly lower than those of the controls (P < 0.05), except for height (P < 0.657).

Table 2 Nutritional status assessment among participants, n (%)/mean ± SD.

	Heart disease (n = 70)	Controls (n = 70)	χ2	P value
Weight (kg)	30.10 ± 12.4	35.41 ± 9.0	2.902	0.004
Height (cm)	132.56 ± 17.0	133.64 ± 11.3	0.444	0.657
Body mass index	16.81 ± 3.6	19.53 ± 2.4	5.219	< 0.001
WAZ score
Severe wasting	12 (17.1)	0 (0.0)	26.102	< 0.001
Wasting	9 (12.9)	0 (0.0)
Normal	48 (68.6)	70 (100.0)
Overweight	1 (1.4)	0 (0.0)
mean ± SD	-1.32 ± 1.5	0.40 ± 0.8	8.380	< 0.001
HAZ score
Severe stunting	5 (7.1)	0 (0.0)	24.409	< 0.001
Stunting	20 (28.6)	2 (2.9)
Normal	45 (64.3)	68 (97.1)
mean ± SD	-1.31 ± 1.3	-0.54 ± 0.7	4.247	< 0.001
BAZ score
Severe underweight	9 (12.9)	0 (0.0)	28.084	< 0.001
Underweight	3 (4.3)	0 (0.0)
Normal	48 (68.6)	35 (50.0)
Overweight	9 (12.9)	33 (47.1)
Obese	1 (1.4)	2 (2.9)
mean ± SD	-0.66 ± 1.6	0.93 ± 0.7	7.472	< 0.001

WAZ: Weight for age Z score; HAZ: Height for age Z score; BAZ: Body mass index for age Z score.

Prevalence of malnutrition

It was found that 48.6% had malnutrition in the heart disease group compared to 4.3% from the control group (P < 0.001) as shown in Figure 2.

Figure 2 Prevalence of malnutrition among the participants.

Relationship between socio-demographic characteristics and malnutrition among children with heart disease

Table 3 demonstrates a higher prevalence of malnutrition among females, children of lower socio-economic status, and those with a history of previous abuse; however, these associations did not reach statistical significance.

Table 3 Association between malnutrition and socio-demographic characteristics among children with heart disease, n (%).

	Normal nutrition (n = 36)	Malnutrition (n = 34)	χ2	P value
Age group (years)
7-9	12 (48.0)	13 (52.0)
10-12	15 (51.7)	14 (48.3)	0.268	0.875
13-16	9 (56.2)	7 (43.8)
Sex
Female	14 (42.4)	19 (57.6)	2.026	0.155
Male	22 (59.5)	15 (40.5)
Social economic status
Lower	10 (47.6)	11 (52.4)	0.282	0.869
Middle	23 (52.3)	21 (47.7)
Upper	3 (60.0)	2 (40.0)
Living with parent
Yes	31 (49.2)	32 (50.8)	1.245	0.264
No	5 (71.4)	2 (28.6)
Previous abuse
Yes	2 (25.0)	6 (75.0)	2.526	0.112
No	34 (54.8)	28 (45.2)

Relationship between anthropometry and some clinical factors

Table 4 shows that malnutrition was more frequent among children with cyanotic CHD, those who had not undergone definitive cardiac surgery (particularly those with palliative repair), and those with one or two prior hospital admissions. However, these associations were not statistically significant.

Table 4 Association between malnutrition and clinical characteristics among children with heart disease.

	Normal nutrition (n = 36)	Malnutrition (n = 34)	χ2	P value
Classification of heart disease
Congenital cyanotic	12 (42.9)	16 (57.1)
Congenital acyanotic	16 (50.0)	16 (50.0)
Acquired	8 (80.0)	2 (20.0)	4.118	0.128
Cardiac surgery type
Definitive surgery	11 (61.1)	7 (38.9)
Palliative surgery	0 (0.0)	3 (100.0)	3.855	0.145
None	25 (51.0)	24 (49.0)
Admissions in last one year
None	9 (50.0)	9 (50.0)
Once	9 (40.9)	13 (59.1)
Twice	6 (46.2)	7 (53.8)
Three or more	12 (70.6)	5 (29.4)	3.632	0.304

Acquired heart disease included dilated cardiomyopathy, rheumatic heart disease and supraventricular tachycardia.

DISCUSSION

Demographic findings: Most participants in the current study were aged 10-12 years, with a mean age of 10.5 ± 2.7 years. This study reveals a slight predominance of females over males; however, global consensus remains elusive, as significant gender differences are observed within specific heart disease subgroups[9]. Most participants in this study had a middle socioeconomic status. The predominance of middle-class participants in both groups likely reflects the broader economic demographics of the population accessing care at the study site, which serves both public and privately referred patients. Additionally, it may be indicative of the shifting economic landscape in the country, where a substantial portion of the population falls within the middle-income bracket due to changing income levels, urbanization, and increased access to education and healthcare[10,11].

In this study, all anthropometric indices were significantly lower in children with heart disease compared to controls. Specifically, weight-for-age, height-for-age, and body mass index-for-age Z-scores were consistently reduced in the heart disease group. Nearly half (48.6%) of children with heart disease were malnourished, in contrast to only 4.3% of the control group. Hence, the alternate hypothesis of this study, which states that there is a statistically significant difference in the nutritional status of children with heart disease attending the outpatient clinic of the Lagos State University Teaching Hospital, Lagos, compared with apparently healthy controls, is accepted.

The presence of CHD can adversely affect nutritional status through altered basal metabolic rate, inefficient energy utilization, and complications such as chronic heart failure, which reduce dietary intake while increasing metabolic demands, thereby compromising growth potential[5,6]. The comparable height observed between the two groups may be due to the predominance of acyanotic CHD in the study population, as these children are less affected by chronic hypoxia. In contrast, chronic hypoxia in cyanotic CHD has been associated with reduced growth hormone secretion and impaired bone strength, which can hinder linear growth[12,13]. The limited impact of hypoxia in acyanotic CHD may thus explain the preservation of height. Although evidence is limited, this highlights the complex role of hypoxia in growth regulation and the need for further research.

Within the heart disease cohort, nutritional status varied by disease severity and treatment status. Children with complex congenital heart defects had higher rates of malnutrition than those with less severe lesions. Likewise, those who had not undergone definitive corrective surgery, particularly those with only palliative repair, demonstrated poorer nutritional outcomes compared to children who had definitive surgical correction. This observation is consistent with previous findings suggesting that surgical correction reduces metabolic stress, improves feeding tolerance, and promotes catch-up growth[6].

Another important observation was the association between frequent hospital admissions and lower anthropometric indices. Interestingly, malnutrition was more common among children with one or two admissions compared to those with three or more. This seemingly paradoxical finding may reflect survivor bias, as children with multiple admissions are often under closer medical surveillance and may benefit from hospital-based nutritional interventions or caregiver education during repeated contacts with the health system. In contrast, those with fewer admissions may not receive such support, leaving them more vulnerable to undernutrition. Another plausible explanation is that children with ≥ 3 admissions may represent those with heart failure who are aggressively managed with diuretics and nutritional supplementation, which can help preserve nutritional status despite frequent hospitalization. This was the case in two out of the five patients with three or more admissions. Also, three out of the five with three or more admissions had tetralogy of Fallot. Chronic hypoxia in cyanotic CHD is known to impair linear growth and contribute to stunting, even without frequent admissions[14].

In general, recurrent hospitalizations also likely reflect greater disease severity, increased infection burden, and disruption of normal feeding routines, all of which can adversely affect nutritional status. These findings underscore the multifactorial nature of growth failure in pediatric cardiac patients, influenced by both physiological and social determinants of health.

Limitations of the study

This study was conducted in a single tertiary hospital (Lagos State University Teaching Hospital), which may limit the generalizability of the findings to all Nigerian children with heart disease. Nutritional outcomes are influenced by factors such as regional variations in healthcare access, socioeconomic status, and case mix of cardiac lesions. Therefore, caution should be exercised when extrapolating these results beyond this setting.

Future studies should adopt a multi-center approach to provide a broader representation of children with heart disease across Nigeria. Inclusion of a larger, more diverse sample and an expanded age range, especially infants and younger children, will enhance the understanding of their nutritional status. Furthermore, incorporating additional nutritional assessment tools and biochemical markers would allow for a more comprehensive evaluation.

CONCLUSION

This study demonstrated that children with heart disease have significantly poorer nutritional indices compared to their healthy peers, particularly among those who have not undergone definitive surgical repair. These findings underscore the importance of routine nutritional assessment as part of standard care for paediatric cardiac patients. Early detection and proactive management of malnutrition could improve clinical outcomes and quality of life. In addition, earlier access to corrective cardiac surgery is likely to mitigate the nutritional deficits associated with prolonged illness and should be prioritized in health policy and clinical practice.

ACKNOWLEDGEMENTS

We gratefully acknowledge the participants and other healthcare workers involved in their care.