[Thyroid hormone levels and thyroid dysfunction of French adults participating in the SU.VI.MAX study]. / Statut thyroïdien et fréquences des dysthyroïdies chez les adultes inclus dans l'étude SU.VI.MAX en 1994-1995.

Abnormal thyroid function has important public health consequences. However, the various degrees of thyroid dysfunction remain unsettled. The SU.VI.MAX cohort provided a unique opportunity to conduct a cross-sectional study of abnormal thyroid function in a large representative population of 11256 men and women representing the geographic distribution of the French continental adult population. Thyroid status was measured, in fasting blood samples, at baseline in 1994-1995. Serum thyrotropin (TSH) levels (abnormal < 0.4 mU/l or > or =4.0 mU/l) and free thyroxine (fT4) were both performed in duplicate on the same sample. Subjects with previous or present thyroid diseases or who were taking thyroid hormones or antithyroid drugs (n=920) were excluded (8.1%). Thus, the final study group consisted of 10346 subjects, 4121 men aged 45-60 years (mean +/-SD) (51.8+/-4.7 yrs), 2641 women aged 35-44 years (40.6+/-2.8 yrs), and 3584 women aged 45-60 years (51.4+/-4.4 yrs). Median (2.5th and 97.5th percentiles) for TSH (mU/l) were 1.52 (0.20-4.54) for men, 1.78 (0.22-5.54) for women aged 35-44 years, and 1.96 (0.22-6.80) for women aged 45-60 years. The TSH distribution of women was shifted to the right compared with men. Arithmetic mean fT4 (+/-SD) was 10.7+/-1.7 ng/l (13.8 +/-2.2 pmol/l) for men and 10.9+/-1.8 ng/l (14.0+/-2.3 pmol/l) for women. The prevalence of abnormal TSH values in men, and in women (35-44 yrs and 45-60 yrs) were TSH<0.4 mU/l 7.0%, 5.3% and 4.4%; TSH 4.0-9.9 mU/l 4.0%, 7.2% and 11.1% and TSH > or =10.0 mU/l 0.2%, 0.4% and 0.7%, respectively. Geometric mean serum TSH and arithmetic mean serum fT4 concentrations showed significant overall inter-regional differences for men and women (p<0.0001). There was also an inter-regional difference in the prevalence of thyroid dysfunction for men (p=0.003), and for the older group of women (i.e. > or =45 yrs) (p=0.04) exclusively. Over the age of 45 years, the women: men ratio for unrecognized elevated TSH levels (> or =4.0 mU/l) was 2.82, whereas it was 0.64 for low TSH levels (<0.4 mU/l). In summary, abnormal TSH values and thyroid dysfunction were more prevalent in women than men, increased with age and were significantly associated with environmental factors. A high prevalence of identified thyroid diseases in the French population was confirmed by the high number of subjects in this study with laboratory evidence of abnormal biochemical thyroid function. Further studies are needed to determine the geographical determinants of thyroid dysfunctions, especially regional differences in iodine intakes, and to assess the long-term adverse effects of biochemical thyroid dysfunction on all-cause morbidity.

[Ultrasonic assessment of thyroid nodules, and iodine status of French adults participating in the SU.VI.MAX study]. / Nodules thyroïdiens à l'échographie et statut en iode des adultes volontaires de l'étude SU.VI.MAX.

Thyroid nodules were assessed by ultrasound in 3 621 presumably healthy free-living French subjects participating in the SU.VI.MAX cohort (2 160 females aged 35-60 years and 1 461 males aged 45-60 years). Urinary iodine was measured in all participants in random morning urine samples. Nodular thyroid structures ranging from 3 mm to 57 mm in diameter were found in 14.5% of the population, without significant differences between regions in the different age and sex groups. Single nodules and multiple lesions were found in, respectively, 9.7% and 3.1% of the subjects. In females, nodules increased from 12.9% to 19.2% between 35-45 years and 45-60 years, respectively (p<0.001). Thyroid nodularity was more frequent among women aged 45-60 years than among men of those ages (19.2% vs. 11.0%, p=0.001). Descriptive data provided by ultrasound differentiated the nodules into solid (43.4%), cystic (38.4%), and mixed solid-cystic (18.2%). Most solid thyroid nodules, 76.1%, were hypoechoic, while 16.6% were iso-, and 7.3% were hyperechoic. The median of iodine concentrations (n=3 276) was 8.0 microgram/100 ml, with 19.4% of the samples being<5 microgram/100 ml. Median iodine concentrations displayed wide regional variations, with values significantly higher in residents of western regions than among those living in the eastern areas (p<0.001), independently of age and sex. No relationship was found between prevalence of nodular thyroid structure and the state of borderline iodine status observed in France.

Determinants of thyroid volume in healthy French adults participating in the SU.VI.MAX cohort.

OBJECTIVE: To study the relative importance of determinants of thyroid volume. DESIGN: Cross-sectional study on a sample of subjects issued from the SU.VI.MAX cohort. SUBJECTS: 2987 French subjects (1713 women aged 35-60 years and 1274 men aged 45-60 years). None of them had previous or present thyroid disease. MEASUREMENTS: Thyroid volume was determined by ultrasound. Serum TSH and free thyroxine (fT4) were measured in duplicate. Urinary iodine and urinary thiocyanate were assayed in random morning urine samples. RESULTS: For both sexes, thyroid volume (ml) was positively correlated with weight, height, body mass index and body surface area (P = 0.0001) and negatively with age for females (P = 0.0009). When the urinary iodine concentration was adjusted for urinary thiocyanate concentration and their interaction, the thyroid volume was negatively correlated with urinary iodine (males P = 0.02, females P = 0.006) and positively correlated with urinary thiocyanate (males P = 0.0001, females P = 0.004). Mean thyroid volume was greater among active smokers than non-smokers (males P < 0.0001, females P = 0.0004) and was greater among former smokers than among non-smokers (males P = 0.0001, females = 0.004). Free T4 and thyroid volume were positively correlated for both sexes (P = 0. 0001). TSH was negatively correlated with thyroid volume for both groups (P = 0.0001). Female users of oral contraception (aged 35-45 years) had a smaller thyroid volume than non-users (P = 0.0009). CONCLUSIONS: The state of borderline iodine deficiency observed in France, in association with a slightly goitrogenic environment, may result in sustained stimulation of the thyroid, independently of TSH level, and is of paramount importance in the formation of goitre. Smoking may affect the thyroid, inducing marked long-lasting thyroid enlargement.

Determining factors in the iron status of adult women in the SU.VI.MAX study. SUpplementation en VItamines et Minéraux AntioXydants.

The iron status of a national sample of adults living in France and participating in the SU.VI.MAX cohort, was assessed using serum ferritin and hemoglobin concentrations. Complete data were obtained for 6648 women 35-60 y old and for 3283 men 45-60 y old. Assessment of iron dietary intakes was realized on a subsample of 3111 women and 2337 men who reported six 24 h dietary records during a one-year period; 22.7% of menstruating women and 5.3% of post-menopausal women presented a total depletion of iron stores (serum ferritin < 15 microg/l). Iron-deficient anemias were found in, respectively, 4.4% and less than 1% of these women. Three-quarters of the anemias were related to iron deficiency in menstruating women. In men, iron depletion and iron deficiency anemia were very rare. Post-menopausal women had much higher serum ferritin levels than menstruating women. In menstruating women, those using intrauterine devices had significantly lower serum ferritin levels than those without contraception, and much lower than those using oral contraception. The frequency of iron depletion reached 28.1% in women using intrauterine devices, but only 13.6% in those using oral contraceptives. The mean iron intake was 16.7 +/- 5.7 mg/d in men and 12.3 +/- 3.4 mg/d in women. Heme iron represented respectively, 11.1 and 10.4% of iron intake. Ninety-three percent of menstruating women had dietary iron intakes lower than recommended dietary allowances (RDA); 52.6% consumed less than two thirds of these RDA. In post-menopausal women and men, respectively 27.7% and 3.6% had dietary intakes lower than RDA. Serum ferritin was positively correlated with meat, fish and total iron intake, and negatively correlated with dietary products consumption, calcium and fiber intake.

Effects of supplementation with a combination of antioxidant vitamins and trace elements, at nutritional doses, on biochemical indicators and markers of the antioxidant system in adult subjects.

OBJECTIVE: To test the impact of supplementation with nutritional doses of antioxidant nutrients on biochemical indicators of vitamin and trace element levels. DESIGN: A randomized double-blind trial was performed comparing two groups receiving daily either a combination of vitamins (beta-carotene, 6 mg; vitamin C, 120 mg; and vitamin E, 30 mg) and trace elements (zinc, 20 mg; and selenium, 100 micrograms); or a placebo. SUBJECTS: 401 subjects (166 males aged 45 to 60 years and 235 females aged to 35 to 60 years). MEASURE OF OUTCOME: Biological markers of vitamin and trace element status and free radical parameters were measured initially, 3 months, and 6 months after supplemention. RESULTS: Mean serum concentrations of alpha-tocopherol, vitamin C, beta-carotene, zinc and selenium increased significantly after 3 months of supplementation in the group receiving multivitamins associated with minerals. At baseline, 18.2% of the men and 5.1% of the women had low concentrations of serum vitamin C (< 20 mumol/l): 2.4% of the men and 17% of the women presented low concentrations of serum retinol (< 1.4 mumol/l): 18.7% of men and 10% of women had serum beta-carotene < 0.30 mumol/l. None of the study subjects had serum alpha-tocopherol concentrations below the limit cut-off point (< 9.3 mumol/l). Low serum zinc concentrations (< 10.7 mumol/l) were found in 15.1% of men and 23.8% of women. Low serum selenium concentrations (< 0.75 mumol/l) were found in 6% of men and 6.4% of women. A significant increase in plasma and red cell GPx activity was observed in groups receiving supplementation. No modifications were observed after 6 months of supplementation for malondyaldehyde. CONCLUSION: This study demonstrates the efficacy of an intake of antioxidant vitamins and trace elements, given at nutritional doses, on biochemical indicators of vitamin and trace elements status.

Dietary magnesium intake in a French adult population.

Magnesium intake was assessed using six 24-h dietary records during a 1-year period in 5,448 subjects (3,111 women 35-60 yrs old and 2,337 men 45-60 yrs old) in the SU.VI.MAX cohort, selected at a national level in France. The overall mean dietary intake was estimated at 369 +/- 106 mg/day in men and 280 +/- 84 mg/day in women. 77 per cent of women and 72 per cent of men had dietary magnesium intakes lower than recommended dietary allowances; 23 per cent of women and 18 per cent of men consumed less than 2/3 of these RDA. A strong positive correlation existed between energy and magnesium intake (r = 0.79; p < 10(-4)). Slight variations were observed according to socio-professional and educational levels and place of residence. Cereal products represented the main contribution in both men (21 per cent) and women (19.8 per cent). In men, the second source was represented by alcoholic beverages (11.7 per cent), which were a lower source of magnesium in women (5.5 per cent). Dairy products, vegetables, meat and poultry were the other main sources of dietary magnesium intake.

Relationship between urinary iodine concentration and hearing capacity in children.

Urinary iodine excretion was assessed in 1222 healthy children aged 10 months (n = 456), 2 years (n = 368) and 4 years (n = 398) living in the Paris area and originating from continental France (55.2%), North Africa (15.7%), the West Indies (9.7%), West Africa (8.2%), Southeast Asia (5.5%), and southern Europe (5.7%). Iodine excretions (median values) were, respectively, 18.1, 13.4 and 11.6 micrograms/100 ml at 10 months, 2 years and 4 years, and risk of mild to moderate iodine deficiency (< 10 micrograms/100 ml) was 18.0%, 32.3% and 37.2% for the same age groups. Urinary iodine excretion was highest among Southeast Asian children, and lowest among West Africans. Hearing acuity was measured either by conventional mono-aural pure-tone audiometry or by binaural free field testing depending on the child's age. Hearing loss at 4000 Hz and average hearing impairment at speech frequencies (500, 1000 and 2000 Hz) were more severe among children at risk of mild to moderate iodine deficiency (less than 10 micrograms/100 ml) compared with those with urinary excretion above 10 micrograms/100 ml.

Iodine intakes assessed by urinary iodine concentrations in healthy children aged ten months, two years, and four years.

Urinary iodine excretion was assessed in 642 healthy children aged 10 mo (n = 243), 2 yr (n = 183), and 4 yr (n = 216) living in the Paris area and originating from continental France (60.3%), North Africa (13.8%), the West Indies (9.1%), West Africa (8.3%), Southeast Asia (4.8%), and southern Europe (3.8%). Mild impairment of neurological (reflexes, tone, audiometry) and intellectual development (Brunet-Lézine scale) was assessed in relation to iodine status. Iodine excretions (median values) were 18.4, 11.9, and 10.9 micrograms/100 mL at 10 mo, 2 yr, and 4 yr, respectively, and risk of mild iodine deficiency (5-10 micrograms/100 mL) was 18.1%, 34.8%, and 38.3% for the same age groups. No relationship was found between anthropometry, global development quotient, and iodine status. High hearing thresholds were more commonly associated with lower iodine excretion, suggesting mild hearing defects. In spite of iodine prophylaxis, the risk of mild to moderate iodine deficiency still exists in France and in a number of European countries. Evaluation of neurological sequels of borderline iodine status is a major public health problem in European communities.

[Oral and intravenous bepridil in the treatment of recurrent sustained ventricular tachycardias. Electropharmacological study]. / Le bépridil intraveineux et oral dans le traitement des tachycardies ventriculaires soutenues récidivantes. Etude électropharmacologique.

The antiarrhythmic properties of bepridil on ventricular tachycardia (VT) termination and prevention were studied in 16 patients using programmed electrical stimulation techniques. All patients were admitted for documented sustained VT resistant to 3.5 +/- 2.4 antiarrhythmic agents. Intravenous bepridil (2 mg/kg) successfully terminated 4 out of 8 and prevented 3 out of 8 patients with hemodynamically well tolerated sustained VT. Oral bepridil (800 mg day 500-600 mg the following days) prevented successfully pacing-induced VT in 7 patients (43.7 p. cent) and a partial result was obtained in additional 3 (18.7 p. cent). In 6 patients bepridil failed to prevent pacing-induced VT including 2 patients with a shorter cycle length on bepridil (classified as aggravation). Tachycardia cycle length lengthened in the remaining 4 a mean of 11 +/- 12 p. cent. One of the 7 patients with a good result presented on bepridil evidence of sinus node dysfunction. The remaining 6 underwent long-term therapy (600 mg/24 h). During a mean follow up of 19 +/- 4 months, 4 patients are well controlled, 1 presented a side-effect (paralytic ileus) and 1 a recurrence. This study emphasizes the antiarrhythmic properties of bepridil at the ventricular level and provides evidence of its usefulness in patients with recurrent sustained VT.