Open Access Research

Associations among total and food additive phosphorus intake and carotid intima-media thickness – a cross-sectional study in a middle-aged population in Southern Finland

Suvi T Itkonen1, Heini J Karp1, Virpi E Kemi1, Elina M Kokkonen2, Elisa M Saarnio1, Minna H Pekkinen3, Merja UM Kärkkäinen1, E Kalevi A Laitinen4, Maila I Turanlahti5 and Christel JE Lamberg-Allardt1*

Author Affiliations

1 Department of Food and Environmental Sciences Calcium Research Unit, University of Helsinki, P.O. Box 66, Helsinki 00014, Finland

2 Department of Food and Environmental Sciences, University of Helsinki, Helsinki, Finland

3 Department of Medical Genetics, Folkhälsan Institute of Genetics, University of Helsinki, Helsinki, Finland

4 Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Helsinki, Finland

5 Department of Pediatric Cardiology, Children’s Hospital, Helsinki University Central Hospital and University of Helsinki, Helsinki, Finland

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Nutrition Journal 2013, 12:94  doi:10.1186/1475-2891-12-94

Published: 10 July 2013

Abstract

Background

Dietary phosphorus (P) intake in Western countries is 2- to 3-fold higher than recommended, and phosphate is widely used as a food additive in eg. cola beverages and processed meat products. Elevated serum phosphate concentrations have been associated with cardiovascular disease (CVD) risk factors and CVD itself in several studies in patients with renal dysfunction and in a few studies in the general population. Carotid intima-media thickness (IMT) is a CVD risk factor, thus the aim of the study was to determine if an association between dietary P, especially food additive phosphate (FAP), intake, and IMT exists.

Methods

Associations among total phosphorus (TP) and FAP intake and carotid IMT were investigated in a cross-sectional study of 37- to 47-year-old females (n = 370) and males (n = 176) in Finland. Associations among TP intake, FAP intake, and IMT were tested by analysis of covariance (ANCOVA) in quintiles (TP) and sextiles (FAP) using sex, age, low-density/high-density lipoprotein cholesterol ratio, smoking status, and IMT sonographer as covariates.

Results

No significant associations were present between TP or FAP intake and IMT (p > 0.05, ANCOVA), but in between-group comparisons some differences were found indicating higher IMT among subjects with higher P intake. When testing for a significant linear trend with contrast analysis, a positive trend was observed between energy-adjusted TP intake and IMT among all subjects (p = 0.039), and among females a tendency for a trend existed (p = 0.067). Among all subjects, a significant positive linear trend was also present between FAP intake and IMT (p = 0.022); this trend was also seen in females (p = 0.045). In males, no significant associations or trends were noted between TP or FAP intake and IMT (p > 0.05).

Conclusions

Our results indicate that a significant linear trend exists between energy-adjusted TP intake and FAP intake, and IMT among all subjects. Based on these results, high dietary P intake should be further investigated due to its potential association with adverse cardiovascular health effects in the general population.

Keywords:
Phosphorus; Phosphate; Carotid intima-media thickness; Cardiovascular risk factors