International Press Center

Contrary to lay beliefs, current perceived stress is not consistently associated with the incidence of high blood pressure (BP) in prospective studies, possibly because of moderating factors. The present prospective study examined this association and explored the potential moderating effects of sex or occupational status. The 4-item Perceived Stress Scale was filled at baseline by 19 766 normotensive adults (13 652 men, mean age ± SD: 46.8 ± 9.3 years), without history of cardiovascular and renal disease, and not on either psychotropic or antihypertensive drugs. After a mean follow-up of 5.8 ± 2.1 years, 3774 participants (19.1%) had high BP, defined as having a SBP at least 140 mmHg or a DBP at least 90 mmHg, or using antihypertensive drugs. There was a significant interaction between baseline-perceived stress and sex (P = 0.02) in relation to high BP at follow-up. After adjustment for potential confounders, baseline perceived stress was associated with high BP at follow-up in women [odds ratio 1.20, 95% confidence interval 1.03-1.38, P = 0.016). In addition, the interaction between perceived stress and occupational status was significant among women (P = 0.02). Baseline-perceived stress was positively associated with high BP at follow-up among women of medium or low occupational status, with odds ratio suggesting a linear increase of the risk (P = 0.005). Perceived stress may be considered as a risk factor for hypertension in women of lower occupational status. Research addressing the relationships between stress and high BP should systematically look for possible interactions with sex and occupational status.

We studied the effects of breast milk feeding versus formula feeding during the first 8 weeks of life on the development of local gastrointestinal humoral immune response by measuring fecal secretory immunoglobulin A (SIgA). Forty-four infants were studied and classified into two groups: breast milk (n = 21) and standard Enfamil without iron (n = 23). The fecal specimens were analyzed at birth and 2, 4, and 8 weeks of age. Radial immune diffusion (RID) technique was used to assay the fecal SIgA during these four ages. Marked SIgA changes were detected in the breast milk-fed group. At birth, no fecal SIgA was detected in either group. At 2, 4, and 8 weeks, significant differences were found between the two groups (p4 less than or equal to 0.001 and p8 less than or equal to 0.001). This phenomenon of enhanced fecal SIgA in breast-fed infants versus standard formula-fed infants is not caused solely by the presence of IgA in breast milk; it represents a stimulatory effect of breast milk on the gastrointestinal humoral immunologic development. The possible active stimulatory role of breast milk on the development of immunologic competence and host defense is discussed. These data suggest an additional advantage of breast milk feeding during early life by the protective role of the earlier and enhanced production of SIgA in the gastrointestinal tract.