Helicobacter pylori May Influence Height in Children Independent of Socioeconomic Factors

To the Editors: In October 2001 issue of this journal, Richter et al. (1) reported that Helicobacter pylori (H. pylori) infected children were smaller than H. pylori non-infected children. They designed a cross-sectional, population-based study in 3,315 children and the diagnosis of H. pylori of infection was established by 13C-urea breath test. They found a statistically significant difference in height and weight measurements between H. pylori-infected boys and their H. pylori-negative counterparts. This difference was present but less pronounced in H. pylori-infected versus non-infected girls. It was also stated that H. pylori infection and growth retardation may be caused coincidentally by the same confounding factors such as low socioeconomic status or poor sanitary conditions, but they could not find the sanitary standards of the residence and household crowding as risk factors in another study published by the same group (2). The overall prevalence of H. pylori in their study group was 6 to 7%, which was comparable to the values reported from the other European countries (3,4). Although the mode of transmission of H. pylori has not been established yet, a strong association between H. pylori infection and poor living conditions in childhood has been clearly demonstrated in epidemiological studies from both developed and developing countries (5–8). In a recent study from France, household crowding and intra-familial factors have been proposed as risk factors for acquisition of H. pylori infection (6). Similarly, we recognized that low family income, household crowding of siblings, using coal stove heating as opposed to central heating, and not being breast-fed were important determining factors for acquisition of H. pylori infection in our study group (9–11). It was amazing for us to read that domestic crowding and sanitary standards of the residence were excluded as a risk factor for acquisition of H. pylori infection, although one third of the study population was recruited from a rural area of Leipzig. Since the percentage of immigrants is very high in several regions of Germany, it would be wise to restate the ethnic origin of the study population in this paper. For instance, it has been reported that H. pylori infection was acquired between the second and third years of life among Turkish children living in the city of Ulm, Germany (12), so by the age of 5 to 7, a Turkish child would already have the H. pylori infection for 2 to 4 years. It would be expected that chronic persistent infection caused by H. pylori might be a cause of diminished growth. We would like to report our findings regarding to H. pylori and its possible effect on growth in 327 healthy school children aging between 3 and 12 years (10). The H. pylori status was determined by 13C-urea breath test in the study group. Almost one half of the study population (49.5%) was infected with H. pylori, and the prevalence increased with increase in age (18.2% in children younger than 4 years and 63% in children older than 10 years). Growth was determined by using centile values for height and weight, which were determined by using national standard growth charts. It was found that the lower the weight and height percentile, the higher the prevalence of H. pylori infection in both sexes (P = 0.018 and P = 0.03, respectively). When the z scores were calculated for each child for both anthropometric measurements, the prevalence of H. pylori was even higher in children whose z scores were below −0.100 for weight and height (P = 0.008 and P = 0.05, respectively). The mean paternal height was also lower in H. pylori-infected children but the maternal height was not different between two groups. Since the factors predisposing to growth retardation and H. pylori infection may be overlapping to some extent, we analyzed the relationship between anthropometric measurements and H. pylori infection after adjusting the group for socioeconomic factors. It was found that low body weight was not a risk factor, but short stature was still found to be a risk factor (OR = 1.54 CI: 0.97–2.49, P = 0.08) for H. pylori infection. These findings were comparable with the results of Demir et al. (13) reported from the same geographical region. It can be suggested that H. pylori may be associated with short stature through mechanisms that are independent of poor living conditions, although low socioeconomic status could determine acquisition of infection. The mechanisms by which H. pylori infection might influence growth still need investigation.