Occupational status, educational level, and the prevalence of carotid atherosclerosis in a general population sample of middle-aged Swedish men and women: results from the Malmö Diet and Cancer Study

Food patterns and components of the metabolic syndrome in men and women: a cross-sectional study within the Malmö Diet and Cancer cohort

This study examined the relations between food patterns and five components of the metabolic syndrome in a sample of Swedish men (n = 2,040) and women (n = 2,959) aged 45-68 years who joined the Malmö Diet and Cancer study from November 1991 to February 1994. Baseline examinations included an interview-administered diet history, a self-administered questionnaire, blood pressure and anthropologic measurements, and blood samples donated after an overnight fast. Cluster analysis identified six food patterns for which 43 food group variables were used. Logistic regression analysis was used to examine the risk of each component (hyperinsulinemia, hyperglycemia, hypertension, dyslipidemia, and central obesity) and food patterns, controlling for potential confounders. The study demonstrated relations, independent of specific nutrients, between food patterns and hyperglycemia and central obesity in men and hyperinsulinemia in women. Food patterns dominated by fiber bread provided favorable effects, while food patterns high in refined bread or in cheese, cake, and alcoholic beverages contributed adverse effects. In women, food patterns dominated by milk-fat-based spread showed protective relations with hyperinsulinemia. Relations between risk factors and food patterns may partly depend on gender differences in metabolism or food consumption and on variations in confounders across food patterns.

Respiratory psychophysiology in hypertension research

The pathogenesis of hypertension results from an interaction of genetic and environmental factors. Behavioral factors might participate in sodium sensitive forms of hypertension via a cascade of physiological responses triggered by conditioned inhibition of breathing. When an individual decreases ventilation sufficient to increase pCO2 but not sufficient to activate chemoreceptor reflexes, plasma pH decreases transiently to stimulate a renal mechanism that can expand plasma volume via sodium retention. The combination of high resting pCO2 and high sodium intake elevates resting blood pressure in laboratory animals and healthy human participants. In the natural environment, this mechanism seems to be more important for the development of hypertension in women than in men, perhaps due to differential expression of anger and aggression. Studies are needed to clarify the role of breathing pattern in individual differences in resting pCO2 and the effects of breathing interventions on salt sensitivity and sodium sensitive forms of hypertension.

Association of high resting end tidal CO2 with carotid artery thickness in women, but not men

BACKGROUND

A previous study found high resting end tidal CO2 (PetCO2) to be an independent determinant of systolic blood pressure in women, but not men. The present study investigates the association of PetCO2 with the common carotid artery intima-media thickness (IMT) and wall-to-lumen (W/L) ratio in a sample of normotensive men and women.

DESIGN AND METHODS

Resting PetCO2 of 188 healthy volunteers, including 88 men and 100 women, in the Baltimore Longitudinal Study on Aging was monitored continuously for 25 min via a respiratory gas monitor. At another session, carotid artery IMT was determined via high-resolution B-mode carotid ultrasonography. The ratio of IMT to carotid artery diameter was calculated as W/L ratio. Resting blood pressure was determined oscillometrically every 5 min for 20 min during each session.

RESULTS

Univariate associations of PetCO2 with systolic blood pressure (SBP) (P< 001), IMT (P< 001) and W/L ratio (P< 001) were significant in women, but not men. Multiple regression analyses showed that high resting PetCO2 was a predictor of SBP (P < 01), IMT (P< 01) and W/L ratio (P< 01) in women, independent of age, body mass index and SBP. For men, age (P < 001) and SBP (P < 01) were independent predictors of carotid IMT, while age (P< 001) was the only independent predictor of W/L ratio in men.

CONCLUSIONS

This study indicates that PetCO2 can play a role in cardiovascular structure, as well as function, in women, and that the relationship is independent of the association of PetCO2 with blood pressure.