Dietary counseling is associated with an improved lipid profile in children with familial hypercholesterolemia
Introduction
Familial hypercholesterolemia (FH) is an autosomal dominantly inherited disease, mainly caused by a mutation in the gene encoding the low-density lipoprotein (LDL) receptor [1] resulting in a two-to threefold increase in circulating LDL cholesterol (LDL-C) levels [1], [2]. Treatment of FH is a lifelong process, as it is the total life-long exposure to LDL-C that may eventually lead to events of coronary heart disease [3]. Both medical and dietary treatments are recommended. The treatment target for primary prophylaxis in heterozygous FH is LDL-C below 3.5 mmol/L for children and below 2.5 mmol/l for adults [3]. However, in children cholesterol-lowering medication is not recommended until they reach the age of 8–10 years [4]. Total cholesterol (TC) and LDL-C levels can be modulated by dietary intake of fatty acids and cholesterol [5] and dietary recommendations are the first-line therapy before cholesterol-lowering medication may be initiated in children [6]. The dietary recommendations are according to the National Cholesterol Education Program (NCEP) and include the principles of a cholesterol-lowering diet, emphasizing a reduced intake of fat, especially saturated fat (SFA), and dietary cholesterol [7], [8].
Studies have shown that dietary adjustments can reduce plasma cholesterol levels by 10–30% in non-FH subjects [9], [10], [11]. However, a recent Cochrane review found that data were not adequate to conclude about the effectiveness of dietary modifications in FH subjects, except for that of plant sterols [12]. A review by Katan et al. concluded that the LDL-C can be lowered by 10% if consuming two grams of plant sterols per day, and that there was sufficient evidence to encourage the use of plant sterols in persons with elevated plasma cholesterol levels [13]. Little is known about the recommended cholesterol-lowering diet on plasma cholesterol in FH children. The aim of the study was therefore 1) to characterize the diet in children with FH with particular focus on dietary fat quality, 2) to investigate the relation between fat intake and plasma cholesterol levels, and 3) to investigate the effect of the dietary advices on plasma cholesterol levels in non-statin and non-plant sterol treated FH children.
Section snippets
Study sample
All children with FH aged 5–18 years that had an appointment at the outpatient Lipid Clinic, Oslo University Hospital, from September to December 2013 were invited to participate in the study. The children were invited to attend one study visit, subsequent to the already pre-scheduled appointment at the Lipid Clinic. Some of the children had never been to the Lipid Clinic before, other children had previously had an appointment at the Lipid Clinic (hereafter named follow-up patients).
Results
Characteristics of the study sample are shown in Table 1. The median age was 12 years (5–18 years, min-max). As expected, both TC and LDL-C were higher in the FH children compared to reference values. All other blood values were within normal range for age. There were few differences between girls and boys, except for plasma vitamin D levels which were significantly higher in girls (p = 0.004), and as expected, girls had a significantly higher plasma level of estradiol (p = 0.002) and a
Discussion
In the present study, intake of saturated fat was positively associated with plasma TC, LDL-C and apo B levels in FH children. A new and important finding was that the plasma lipid profile was improved in FH children after dietary counseling where focus was on reducing intake of SFA and dietary cholesterol despite the fact that FH children had higher intake of SFA than what is recommended.
Studies in children with FH have shown that initiation of statin therapy is safe when started from the age
Conflict of interest
During the past five years, Retterstøl has received honoraria for lectures or expert meetings from Merck, Pfizer, Mills DA, Melk.no, Apotek1, Pronova, Amgen, Genzyme, and Sanofi; none of which are related to the contents of this manuscript. During the past five years Holven has received research grants or honoraria from Tine, Mills, and Olympic Seafood, and Amgen; none of which are related to the contents of this manuscript. The rest of the authors declare no conflict of interest.
Financial support
This work was supported by grants from The Throne-Holst Foundation for Nutrition Research, Oslo, Norway, The National Advisory Unit on FH, Oslo University Hospital and the University of Oslo, Oslo, Norway.
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