Tuesday, August 12, 2008

Asthma in Puerto Rican Children

I feel like I never blog anymore!!

No seriously, I have been super busy lately, so I probably won't be posting as many "fun" blogs, although I still have lots of pictures and stories to share, so I will get to them eventually.

But for now, I thought you might like to read a little tidbit on asthma. Did you know that Puerto Ricans have far and away the highest rates of asthma of all racial and ethnic groups in the United States? And despite some well-formed hypotheses, we still aren't entirely sure why. Read on!

The Facts:

Puerto Ricans have the highest asthma prevalence among all racial and ethic groups in the United States. In a large-scale study of Latino populations, one out of every five Puerto Rican children between 6 months and 11 years were reported to have ever had asthma.1 In Connecticut, where the majority of Latinos are of Puerto Rican descent, it was shown that 24.5% of Latino families have at least one asthmatic child, compared to 17.7% for African Americans and 9.6% for Whites, and that these differences are not accounted for by socioeconomic status or maternal age.2 Connecticut’s Hispanic children have a lifetime asthma prevalence rate of 18.4%, compared to 11.3% for blacks and 7.4% among non-Hispanic whites.2 Disparities in the prevalence of asthma in Puerto Rican children persist even among Latino subgroups. The lifelong prevalence among mainland Puerto Ricans is 20.1%, compared to 8.8% among Cuban Americans and 4.5% among Mexican Americans.1 Of the estimated half-million Latino children with asthma in the United States, a whopping 2/3 are Puerto Rican1, despite the fact that the large majority of US Latinos are Mexican Americans. Age of onset is also earlier for Puerto Ricans than Mexican American children, with more than 50% of Puerto Rican children having their first asthma attack before 1 year of age.1

Why?

Many studies have tried to investigate the reasons for the tremendous discrepancy in asthma prevalence among Puerto Ricans, and most hypotheses are now multi-factorial, including genetic, socioeconomic, and cultural factors. Genetic studies of inflammatory response processes indicate that many Puerto Rican children with asthma have increased levels of a variant alpha1-antitrypsin phenotype.5 Alpha1-antitrypsin is a glycoprotein that protects delicate tissues from inflammatory cell enzymes. It was speculated by the authors that the presence of this variant form may predispose these children to asthma.

Interesting evidence that may support a “genetic” hypothesis in Puerto Ricans comes from the drastically different asthma prevalence among Mexican Americans. Despite having a lower socioeconomic status than whites and a lower rate of health insurance than Puerto Ricans, Mexican Americans have significantly lower rates of asthma than both of these groups, even when controlled for socioeconomic status and parental smoking behavior. 1,4 Initial and serial testing of pulmonary function in Mexican American and white children showed non-Mexican-American children had significantly lower maximum expiratory flows (Vmax50%) in each year of testing, suggesting that Mexican American children may have larger airways than their white counterparts.4 Perhaps further studies will investigate more fully the differences in pulmonary function of Puerto Rican children.

Other studies point to the living conditions of Puerto Rican children as a possible explanation for their high rates of asthma. Puerto Rican children are the poorest children in the United States6, and it is well documented that poverty increases risk for certain illnesses. Other studies have suggested still other risk factors, such as differences in family structure and migration patterns, that may account for some of the discrepancy in prevalence.7 It has been reported that among Latinos, Puerto Rican women of reproductive age are more likely to smoke (33.5%) than Mexican American (23.2%) or Cuban women (22.6%), thus putting children at greater risk of complications due to second hand smoke.3 Another risk factor for asthma is prematurity and low birth-weight,8 and it has been suggested that the high rate of low birth-weight births to Puerto Rican mothers may also play a role in the development of childhood asthma among Puerto Rican children.

1.

Charter-Pokras, O.D., & Gergen, P.J. (1993). Reported asthma among Puerto Rican, Mexican-American, and Cuban children, 1982 through 1984. American Journal of Public Health, 83, 580-582.

2.

Beckett, W.S., Belanger, K., Gent, J.F., Holford, T.R., & Leaderer, B.P. (1996). Asthma among Puerto Rican Hispanics: A multi-ethnic comparison study of risk factors. American Journal of Respiratory and Critical Care Medicine, 154, 894-899.

3.

Pletsch, P.K. (1991). Prevalence of cigarette smoking in Hispanic women of childbearing age. Nursing Research, 40, 103-106.

4.

Dodge, R. (1983). A comparison of the respiratory health of Mexican-American and non Mexican-American white children. Chest, 84, 587-592.

5.

Colp, C., Pappas, J., Moran, D., Lieberman, J. (1993). Variants of alpha 1-antitrypsin in Puerto Rican children with asthma. Chest, 103, 812-815.

6.

Bureau of the Census. (1997). Selected social characteristics of all persons and Hispanic persons by type of origin. Retrieved August 12, 2008 from

7.

Lara, M., Morgenstern, H., Duan, N., Brook, R.H. (1999). Elevated asthma morbidity in Puerto Rican children: a review of possible risk and prognostic factors. West J Med, 170, 75-84.

8.

Oliveti, J.F., Kercsmar, C.M., Redline, S. (1996) Pre- and perinatal risk factors for asthma in inner-city African American children. Am J Epidemiol, 143, 570-577.

3 comments:

Speaking Boricua said...

Great post, I just had to link to it.

Petra H said...

Very interesting post regarding an important subject. But I have to say, concerning the theory about smoking, that I am impressed by how few people smoke in Puerto Rico - compared to many countries in Europe. I don't know the rates of asthma in for example Spain, France or Greece but people definitely smoke more in those countries. However, maybe Puerto Ricans living in the US smoke more than the Puerto Ricans living in PR?!

Renee said...

Puerto Ricans in the US actually do smoke more than on the island, but the rates of asthma on the island are basically the same-unbelievably high. I really think there is a very strong genetic component here.

And yes, Europe does have a high rate of smoking but hopefully that will change in the future!