The biomarker-based validity of a food frequency questionnaire to assess the intake status of folate, pyridoxine and cobalamin among Iranian primary breast cancer patients

• Published in: European journal of clinical nutrition Vol. 68; no. 3; pp. 316 - 323
• Main Authors: Pirouzpanah, S, Taleban, F-A, Mehdipour, P, Atri, M, Hooshyareh-rad, A, Sabour, S
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-03-2014; Nature Publishing Group
• Subjects: 692/699/67/1347; 692/700/2814; Adult; Aged; Area Under Curve; Biological and medical sciences; Biomarkers; Biomarkers - blood; Body Mass Index; Breast cancer; Breast Neoplasms - blood; Cancer patients; Carcinogenesis; Carcinogens; Clinical Nutrition; Diet; Dietary intake; Electrochemiluminescence; Epidemiology; Estimates; European Continental Ancestry Group; Fasting; Feeding. Feeding behavior; Female; Fluorescence; Folic acid; Folic Acid - blood; Food; Food and nutrition; Food habits; Food intake; Fundamental and applied biological sciences. Psychology; Gynecology. Andrology. Obstetrics; Health aspects; High performance liquid chromatography; Homocysteine; Humans; Internal Medicine; Iran; Laboratory testing; Liquid chromatography; Mammary gland diseases; Medical sciences; Medicine; Medicine & Public Health; Metabolic Diseases; Middle Aged; Nutrition Assessment; Nutritional Status; original-article; Physiological aspects; Plasma; Plasma levels; Prospective Studies; Public Health; Pyridoxine; Pyridoxine - blood; Questionnaires; Reproducibility of Results; Sensitivity; Surveys and Questionnaires; Tumors; Validity; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Vitamin B; Vitamin B 12 - blood; Vitamin B12; Vitamin B6; Iran; Asia; food frequency questionnaire; breast cancer; folate; cobalamin; validation study; total homocysteine; Consumption; Human; Validation; Thiol; Breast disease; Biological marker; Metabolic diseases; B-Vitamins; Breast cancer; Pyridoxine; Malignant tumor; Folate; Sulfur containing aminoacid; Mammary gland diseases; Validity; Homocystein; Primary; Food Frequency Questionnaire; Cancer
• ISSN: 0954-3007; 1476-5640
• DOI: 10.1038/ejcn.2013.209

Background/Objectives:
Folate, pyridoxine and cobalamin are coenzymatically essential in one-carbon methyl metabolism, and their deficiencies could explain some alterations during breast carcinogenesis. We aimed to evaluate the validity of folate, pyridoxine and cobalamin estimates from a food frequency questionnaire (FFQ) on the basis of their corresponding fasting plasma biomarkers, in breast cancer (BC) patients.
Subjects/Methods:
In a prospective, consecutive case series, 149 women with primary BC aged between 30 and 69 years as a representative sample of Iranian women with BC were recruited. The 136-item FFQ was used for the validity assay. Fasting plasma folate and cobalamin were tested by automated electrochemiluminescence. The high-pressure liquid chromatography with fluorescence detection was used to determine the plasma levels of pyridoxal-5'-phosphate (PLP) and total homocysteine (tHcy).
Results:
Area under the curve (AUC) for assessing the diagnostic accuracy of folate-related data through an FFQ was 0.74 (
P
<0.01) in the reference model (folate plasma level<5.9 ng/ml), with sensitivity and specificity of 68% and 63%, respectively. The positive and negative predictive values (PPV and NPV) were 96.9% and 96.8%, respectively. The AUC for cobalamin intake in the reference model (plasma cobalamin<260 pmol/l) was 0.64 (
P
<0.01), with 60% sensitivity and 61% specificity. Although tHcy⩾10.0 μmol/l was used as reference indicator, the folate intake (AUC=0.71,
P
<0.01) and cobalamin intake status (AUC=0.67,
P
<0.05) were also determined appropriately by FFQ.
Conclusions:
Dietary folate and cobalamin estimates from FFQ were significantly correlated with their fasting plasma concentrations. Our data supported the validity of new FFQ to rank individuals by dietary intake status of folate and cobalamin.