(Reuters Health) - A study of British children finds that slight height differences track with deprivation, especially among white kids, with children in poor neighborhoods standing up to two-thirds of an inch (1.6 centimeters) shorter than those in rich areas.

“The actual difference in height between the most and least deprived groups is small, but does highlight an ongoing inequality in population health which does need to be addressed,” said lead author Caroline Hancock, a senior public health intelligence analyst at Public Health England.

“I feel that the data helps to highlight and monitor these issues and supports the work of health practitioners who are working to reduce inequalities across the population,” she told Reuters Health by email.

She and her co-authors note in Archives of Disease in Childhood that 80 percent of height differences can be attributed to genetics and the remaining 20 percent to environmental factors like cigarette smoke, poor nutrition, infectious disease and psychological stress.

Hancock, who did the research as part of her master’s thesis, said that environmental factors can be targeted and modified to improve children’s health.

For the study, the researchers analyzed data from a national surveillance program of annual height and weight measurements of one million primary school children in England aged 4 to 5 and 10 to 11 years old.

They focused on data gathered between 2008 and 2013 on white, South Asian and black children in five different areas, categorizing the neighborhoods by socioeconomic factors, ranging from the least to the most deprived.

Because the five-year trends for children of Indian, Pakistani and Bangladeshi descent were similar, the researchers combined them into one Asian group for the analysis and similarly combined black kids from African and Caribbean backgrounds into one black ethnic group.

Overall, heights varied by ethnicity, with the black children tending to be tallest, on average, at both age points. At ages 4 to 5, white children where the shortest on average, but by ages 10 to 11, Asian children were shortest as a group.

At ages 10 to 11, there was an average height difference of 0.66 in (1.6 cm) between boys and of 0.5 in (1.2 cm) between girls in the least and most-deprived neighborhoods.

Black children showed the least difference in height between the most- and least-deprived neighborhoods, followed by Asian kids. In fact, black girls ages 4 to 5 in the most deprived areas had a slightly higher average height compared to those in the least deprived areas. White boys and girls showed the greatest height differences between rich and poor.

Hancock said that more research is needed to explain the findings, adding, “It’s important to note that this is a single study rather than a total look at the evidence and it is an association that may be confounded by a whole range of factors.”

Misha Eliasziew, a biostatistician in the Department of Public Health and Community Medicine at Tufts University Medical Center, pointed out that placing different ethnicities into one group could weaken the results.

She also noted that grouping children by neighborhood wealth is a less precise way of measuring than if the study had looked at individual families’ level of deprivation. Measuring nutrition, hygiene and access to medical care, which all contribute to children’s growth, would also be important, said Eliasziew, who was not involved in the study.

"We know that malnutrition contributes to stunting and that stunting has negative long-term consequences. But . . . stunting is apt to be far more than a half inch to one inch,” she said by email.

Eliasziew said parents should not be worried by the study results. "These are one-half inch differences. Even the height difference between boys and girls is minute (approximately 1 cm = less than one-half inch).”

SOURCE: http://bit.ly/1Qilgcw Archives of Disease in Childhood, online September 4, 2015.