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Parents' cholesterol predicts asthma severity in children
Last reviewed: 27.07.2025
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A new study links parents' metabolic health and baby's birth weight to asthma severity, finding for the first time that paternal cholesterol levels may have a modest protective effect.
Introduction
Childhood obesity is on the rise worldwide, affecting more than 15% of American children. Associated with this increase is an increased risk of developing asthma. The role of metabolic disorders and obesity in parents in the incidence of asthma in offspring is the subject of a recent study published in Respiratory Research.
Obesity is associated with chronic inflammation and multiple metabolic abnormalities in glucose and lipid metabolism pathways. Abdominal obesity predisposes to elevated blood cholesterol levels and insulin resistance. As a result, such individuals are at increased risk for cardiovascular disease, diabetes, and asthma.
About 17% of American teenagers and 16% of children are obese. These rates have tripled for black and Hispanic children over the past four decades. Similar trends are seen in Europe.
Unlike most asthma cases worldwide, the unique asthma phenotype seen in most patients with obesity-associated asthma reflects an inflammatory rather than allergic nature of the disease. In children, obesity-associated asthma is characterized by inflammatory cell activation and impaired lipid and glucose homeostasis. The mechanisms underlying these associations are not fully understood, which was one of the motivations for conducting this study.
Maternal obesity before pregnancy and weight gain during pregnancy are thought to be associated with elevated blood lipids (total cholesterol, low-density lipoprotein (LDL, or "bad" cholesterol), and triglycerides). In addition, their offspring are more likely to be obese in childhood and have respiratory illnesses, including wheezing and respiratory infections.
However, the association of paternal weight and metabolic abnormalities with respiratory disease in the offspring remains unclear. The present study examined the association of parental obesity and metabolic markers with dyslipidemia and asthma in their offspring. It also assessed whether birth weight, particularly low weight for gestational age, is associated with asthma outcomes and whether the results can be generalized beyond children receiving inhaled corticosteroids (ICS).
About the study
The study included 29,851 children from the nationwide Danish REASSESS Youth cohort aged 2–17 years (mean age 9 years). Of these, approximately 8,500 had asthma. 1,430 children (5%) had severe asthma, 4,750 (16%) had poorly controlled asthma, and 2,353 (8%) had asthma with episodes of increasing severity. Because the cohort only included children prescribed ICS, the results primarily reflect children with persistent, more severe asthma, rather than all cases of childhood asthma.
Key Results
Lipid and glucose markers in children
Total cholesterol and LDL were elevated in 10% and 11% of about 2,000 children who had lipid markers measured. High-density lipoprotein (HDL, or “good” cholesterol) was low in 15% of children, and about 14% had elevated triglycerides. Elevated hemoglobin A1c (HbA1c) was found in 1.7% of about 5,500 children. However, elevated HbA1c was not an independent predictor of asthma severity, control, or exacerbations.
Metabolic markers and asthma in children
In children, high LDL and triglycerides increased the odds of severe asthma and exacerbating asthma by 2.3-fold and 1.5-fold, respectively. Low HDL was associated with a 1.5-fold increase in the odds of both uncontrolled and exacerbating asthma. In addition, children born small for gestational age (z-score ≤ -2) had a 1.44-fold risk of uncontrolled asthma.
Obesity and metabolic markers in parents
The average body mass index (BMI) of mothers before pregnancy was 23.5 kg/m², with almost 40% of mothers being overweight or obese. About 4% of mothers and 8% of fathers had elevated HbA1c values.
Total cholesterol and LDL were elevated in 30% of mothers and more than 40% of fathers. Triglycerides were elevated in about 20% of mothers and more than 40% of fathers. HDL was low in 18% of mothers and 24% of fathers.
Parental Metabolic Markers and Childhood Asthma
Children born to mothers with elevated total cholesterol, LDL, and triglycerides had a higher risk of uncontrolled asthma. Elevated maternal HbA1c was also associated with uncontrolled asthma. However, although elevated maternal total cholesterol was associated with uncontrolled asthma (OR 1.16), it paradoxically protected against severe asthma (OR 0.83).
Pre-pregnancy maternal overweight and obesity, as well as markers of metabolic dysfunction, predicted a 1.2- to 1.4-fold increased odds of uncontrolled asthma in the child.
In fathers, elevated HbA1c increased the risk of exacerbated asthma in children, and lower HDL was associated with uncontrolled asthma. However, elevated total and LDL cholesterol in fathers had a moderate protective effect against exacerbated asthma (OR 0.96 and OR 0.86, respectively).
Conclusion
Dyslipidaemia in parents or children was a risk factor for asthma in this Danish cohort of children with persistent asthma. This suggests that abnormal lipid metabolism has a transgenerational effect, contributing to asthma through mechanisms other than the direct effect of parental body weight. However, this was a cross-sectional, register-based study with no control group, and data were collected only from children already receiving ICS. The results reflect associations, not proven causation, and cannot be generalised to all cases of childhood asthma.
This study shows for the first time that markers of abnormal metabolism in fathers are associated with asthma outcomes in children. Further research is needed to develop interventions to prevent asthma in offspring.
"The association between maternal weight, pregnancy weight gain, weight for gestational age and asthma risk also requires further study to recommend potential lifestyle changes before or during maternal pregnancy and in early childhood that may improve respiratory outcomes throughout childhood."