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Biomedical subjects

J Tichet

Publications and source records attributed to J Tichet.

At least 37 records · Page 2Linked to original sources
PubMed2000

Puberty-associated differences in total cholesterol and triglyceride levels according to sex in French children aged 10-13 years.

PURPOSE: To assess the relationships between lipid levels and sexual maturity, independently of age-related differences, and to investigate possible differences related to sexual maturity across the percentiles of the lipid distributions. METHODS: Fasting serum total cholesterol and triglyceride concentrations were measured in 6577 boys and 6605 girls, aged from 10 to 13 years, with different Tanner stages. The total cholesterol and triglyceride mean and percentile levels were estimated according to age and Tanner stage by ordinary least squares and percentile regression models, separately in both sexes. RESULTS: In boys and girls, total cholesterol levels were significantly associated with pubertal stage after controlling for age. At age 12, the estimated mean levels in boys varied from 4.82 mmol/L for Tanner 1 to 4.41 for Tanner 5. The corresponding values were 5.05 and 4.62 mmol/L in girls, for whom the association with maturity was stronger in the upper than in the lower percentiles (p < 0.0001); between the extreme Tanner stages, the 95th percentiles of total cholesterol differed by 0.80 mmol/L, in comparison to 0.19 mmol/L for the 5th percentiles. Therefore, 1. 8% of girls and 0.7% of boys were classified differently whether Tanner stage was used or not to assess hypercholesterolemia (concentrations in the upper 5% of the distributions). Triglycerides were positively related to sexual maturity independently of age, but the discrepancies between classifications were lower; 1.1% in girls and 0.4% in boys. CONCLUSIONS: Our findings emphasize the importance of sexual maturity, even for a given age, for interpreting lipid levels in children.

Adolescent↗
PubMed2000

Effects of current smoking and smoking discontinuation on renal function and proteinuria in the general population.

BACKGROUND: Smoking may adversely affect the progression of renal diseases. However, it is unknown whether smoking affects renal function in subjects without nephropathy. METHODS: In 1998, 28,409 volunteers from the general population were examined at the Institut Régional pour la Santé (IRSA). Renal function was estimated with creatinine clearance using the Cockcroft formula. Dipstick proteinuria was assessed on an overnight urine sample by a trained technician. RESULTS: Adjusted creatinine clearance was higher in current smokers than in former smokers and never smokers (100.6 +/- 13.6 vs. 98.8 +/- 13.9 mL/min/1.73 m2, P < 0.0001, and vs. 98.5 +/- 14.0 mL/min/1. 73 m2, P < 0.0001, respectively). This difference was predominant in men and weak in women, and was associated with the number of cigarettes smoked daily. The slope of the projected age-related decline in the creatinine clearance accelerated with age, but it was similar in current smokers, former smokers, and never smokers. Creatinine clearance was associated with a relative risk of proteinuria [for each mL/min/1.73 m2, the relative risk was 1.007 (95% CI, 1.000 to 1.015), P = 0.056, for 1+ or higher proteinuria; and 1.018 (1.004 to 1.030), P = 0.0078, for 2+ or higher proteinuria]. Current and former smokers had a marked risk of 2 or higher proteinuria [adjusted RR (95% CI), 3.26 (1.66 to 6.80), P = 0. 0009, and 2.69 (1.24 to 5.99), respectively, P = 0.013, vs. never smoking], which was independent of the daily or cumulative cigarette consumption. CONCLUSIONS: In the general population, smokers do not exhibit lower creatinine clearance than never smokers. In fact, creatinine clearance is slightly higher in current smokers at least in men, even when normotensive and hypertensive subjects are analyzed separately, but the difference is small, especially in women. This effect seems reversible upon smoking discontinuation. Chronic smoking results in a marked risk of irreversible proteinuria that may occur despite moderate smoking.

Adult↗
PubMed2000

Lack of relationship in long-term type 1 diabetic patients between diabetic nephropathy and polymorphisms in apolipoprotein epsilon, lipoprotein lipase and cholesteryl ester transfer protein. Genétique de la Nephropathie Diabétique Study Group. Données Epidémiologiques sur le Syndrome d'Insulino-Résistance Study Group.

BACKGROUND: Genetic susceptibility contributes to the risk of diabetic nephropathy. Lipid disorders may favour diabetic nephropathy. Thus polymorphisms in lipid metabolism are candidates for the genetic component of risk for diabetic nephropathy. METHODS: We searched for a contribution of the genetic polymorphisms of lipoprotein lipase (LPL), cholesteryl ester transfer protein (CETP) and apolipoprotein epsilon (Apo E) to the development of diabetic nephropathy by studying 494 type 1 diabetic patients with proliferative retinopathy and various stages of diabetic nephropathy (GENEDIAB Study). The selection process ensured that all patients had expressed their risk of chronic complications due to uncontrolled diabetes. Thus the nephropathy stages were largely influenced by genetic background. The lipid profile included fasting plasma total cholesterol (TC), triglycerides (TG), apolipoprotein A1 (Apo A1) and B (Apo B), and lipoprotein (a) (Lp(a)). Genetic polymorphisms were determined by PCR-based detection of Apo epsilon (e2/e3/e4), LPL (mutation Asn 291 Ser) and CETP (TAQ:IB B1/B2). RESULTS: One hundred and fifty-seven patients (32%) had no nephropathy, 104 (21%) incipient nephropathy, 126 (25%) established nephropathy and 107 (22%) advanced nephropathy. There was a significant relationship between the stages of diabetic nephropathy and TC (P=0.002), TG (P<0.0001), Apo B (P=0.0007) or Lp(a) (P=0. 038), but not Apo A1. However the genetic polymorphism distributions of LPL, CETP and Apo epsilon did not differ in terms of renal complications. The study power to reject the null hypothesis was 58% for the Apo epsilon genotypes. CONCLUSION: These results support no or only marginal effects of a genetic basis for lipid disturbances encountered in diabetic nephropathy.

Adult↗
PubMed2000

[Is smoking history a risk factor of arterial hypertension in men?].

Former smokers exhibit decreased cardiovascular risk as compared to smokers who continue to smoke. However, smoking discontinuation results in weight gain which may be important and influence arterial pressure. From January 1st to June 30th, 1998, 12,417 volunteers (aged 20 to 69) were examined at the "Institut régional pour la santé" (IRSA, Regional Institute for Health), a group of 9 social medical centres in Western and Central France. The subjects were screened for a routine medical and biological check-up provided by their medical insurance. All of the subjects were interviewed by a trained nurse who completed a standardised questionnaire regarding personal medical history, current treatments and lifestyle behaviours (especially alcohol and smoking habits). A physician recorded clinical parameters including age, weight, height, systolic and diastolic arterial pressure. Body mass index (BMI) was calculated. Non smokers and former smokers represented 40.0% and 23.8% of the population respectively. The prevalence of a BMI 27.0 kg/m2 or greater was higher in former smokers than non smokers and current smokers. Systolic and diastolic arterial pressure in former smokers exceeded those of current smokers and non smokers by 4.2/1.1 mmHg and 2.8/1.6 mmHg respectively. Using logistic regression analysis, the relative risk of hypertension in former smokers was 1.24 (CI 95%: 1.10-1.39, p < 0.001) and 1.13 (0.995-1.29, p = 0.055) as compared to non smokers and current smokers, after adjustment for age and alcohol intake. Differences became non significant when BMI was entered in the model. The results of the present study suggest that former smoking status is associated with a higher prevalence of overweight which may cause a higher prevalence of hypertension.

Adult↗
PubMed1998

Gene polymorphisms of the renin-angiotensin system in relation to hypertension and parental history of myocardial infarction and stroke: the PEGASE study. Projet d'Etude des Gènes de l'Hypertension Artérielle Sévère à modérée Essentielle.

OBJECTIVE: To investigate a possible involvement of polymorphisms of the renin-angiotensin system in predisposition to moderate and severe hypertension and their relationship to parental histories of myocardial infarction and stroke. METHODS: Hypertensive cases (453 men, 326 women) were patients followed up by general practitioners for established hypertension. Inclusion criteria were an age of onset of hypertension < or = 60 years and a diastolic blood pressure > or = 105 mmHg without antihypertensive medication or > or = 100 mmHg under treatment. Normotensive controls were selected from population-based samples (362 men) and during a preventative medicine visit (170 women). Polymorphisms of the angiotensinogen gene (AGT M235T and T174M), the angiotensin I converting enzyme gene (ACE I/D), and the angiotensin II type 1 receptor gene (AGT1R A1166C) were investigated. RESULTS: The AGTT235 allele prevalence was higher among male hypertensive cases than it was among controls (0.46 versus 0.40, P = 0.01) and a similar trend was observed with female cases whose hypertension had been diagnosed before they were aged 45 years (0.44 versus 0.38, P = 0.20). The AGT1R C1166 allele prevalence was higher among female hypertensives than it was among controls (0.30 versus 0.23, P = 0.03) but no such difference was observed for men. The AGT T174M and ACE I/D polymorphisms were not associated with hypertension. Hypertensive patients reporting a parental history of myocardial infarction before age 60 years had a higher prevalence of the ACE D allele than did those without such a parental history (0.68 versus 0.56, P = 0.01). The ACE D allele prevalence was also greater among patients reporting a parental history of stroke incidence before age 65 years (0.66 versus 0.57, P = 0.05). CONCLUSIONS: These results support the hypothesis that the AGT gene plays a role in predisposition to hypertension and that the ACE gene plays a role in predisposition to acute ischemic events.

Adult↗
PubMed1998

[An example of how to measure the relation between developmental dyslexia and illiteracy].

The ability to read and the phonological fitness of 89 youth (average age of 21.3 years) having difficulty with social and professional integration were examined. We observed that 64% of them (n = 57) had difficulty in reading. The results of the phonological and reading tests showed that developmental dyslexia constitutes, for 56% of the subjects (n = 32), or for 36% of the population of youth with difficulties, the explanatory framework for the delay of acquisition of these capacities. Reading difficulties for these youth were significantly linked to an alteration of the phonological treatment that effects: short-term verbal memory, auditory discrimination and meta-phonological fitness. The data tends to validate the hypothesis of the existence of a functional link between developmental dyslexia and illiteracy.

Adolescent↗
PubMed1998

Insulin dose and cardiovascular risk factors in type 1 diabetic children and adolescents.

Associations between a high daily insulin dose and cardiovascular risk factors, including those of the insulin-resistance syndrome, were studied in 479 Type 1 diabetic children 6 to 18 years of age. Insulin dose increased over the first two years after diagnosis of diabetes (p = 0.0001) and was significantly higher in girls (p = 0.01). For those children with diabetes duration of more than 2 years, the insulin requirement increased up to 13-14 years of age (p < 0.05) and was higher in pubertal than pre-pubertal children (p < 0.05). For girls, the requirement was higher in puberty than in post-puberty (p < 0.05) and increased with diabetes duration (p < 0.05). Triglyceride concentrations were associated positively and significantly with the insulin dose of both boys and girls, after adjustment for age, pubertal stage, diabetes duration, and metabolic control (fructosamine levels). No other consistent associations were found between insulin dose and other cardiovascular risk factors: body mass index, central adiposity, arterial blood pressures, serum total cholesterol, apoA1, apoB, Lp(a), uric acid, or urinary albumin excretion. Parental obesity, hypertension and diabetes were not related to the insulin dose of children. The results did not differ when the population was limited to the 375 children with diabetes duration of more than 2 years. It is concluded that in these Type 1 diabetic children the insulin dose for a given level of metabolic control (our surrogate measure of insulin resistance) was related to a single cardiovascular risk factor: triglyceride concentrations.

Adolescent↗
PubMed1997

Haplotypes of angiotensinogen in essential hypertension.

The M235T polymorphism of the angiotensinogen gene (AGT) has been associated with essential and pregnancy-induced hypertension. Generation of haplotypes can help to resolve whether the T235 allele itself predisposes to the development of hypertension or acts as a marker of an unknown causal molecular variant. We identified 10 diallelic polymorphisms at the AGT locus and genotyped both a series of 477 probands of hypertensive families and 364 controls, all French Caucasians, as well as a series of 92 hypertensives and 122 controls from Japan. Despite a large ethnic difference in gene frequency, a significant association of T235 with hypertension was observed both in Cancasians (.46 vs. .38, P = .004) and in Japanese (.91 vs. .76, P = .002). In both groups, the G-->A substitution located at position -6 upstream of the initial transcription site occurred at the same frequency and in complete linkage disequilibrium with the T235 allele. No other polymorphism was found to be consistently associated with hypertension. Five informative haplotypes subdividing the T235 allele were generated. Whereas two of them were associated with hypertension in Caucasians, none of these two haplotypes (H3 and H4) reached statistical significance in Japanese. The analysis of the AGT-GT repeat revealed marked linkage disequilibriums between each of the diallelic polymorphisms and some (GT)n alleles, with similar patterns in the two populations. The strong disequilibrium between M235 and (GT)16 explained the increased frequency of that particular allele in French controls compared with hypertensives (.42 vs. .36, P < .01). The haplotype combining the M235T and G-6A polymorphisms appears as the ancestral allele of the human AGT gene and as the one associated with hypertension.

Age of Onset↗
PubMed1997

Proposed criteria for the diagnosis of diabetes: evidence from a French epidemiological study (D.E.S.I.R.).

The American Diabetes Association and a working group of the International Diabetes Federation and the World Health Organisation are considering the possibility of lowering the level of fasting glucose for diagnosis of diabetes from 7.8 mM to 7.0 mM (126 mg/dl) and adding a "hyperglycaemia" category (6.1-6.9 mM). This report studied the resulting change in the frequency of diabetes in the French D.E.S.I.R. cohort and evaluated cardiovascular risk factors according to the proposed limits. The frequency of treated diabetes was 1.0% in this cohort of more than 5,000 French men and women 30 to 64 years of age, 0.7% had a fasting glucose > or = 7.8 mM versus 1.6% for the proposed > or = 7.0 mM. Using the new criteria, 3.8% of men and 1.6% of women would be diabetic. For many cardiovascular risk factors, men with fasting glucose > or = 7.8 mM had a significantly higher risk than those in the (7.0-7.7 mM) range, whereas no significant differences were found for women. There were few differences between the (7.0-7.7 mM) and (6.1-6.9 mM) ranges, but highly significant differences were apparent for both sexes between the normoglycaemic (< 6.1 mM) and hyperglycaemic (6.1-6.9 mM) categories. The percentage of men with two or more of ten risk factors increased with fasting glucose: 36% in the normoglycaemic (< 6.1 mM) and 49% in the hyperglycaemic (6.1-6.9 mM) categories; 73% with fasting glucose in (7.0-7.7 mM) versus 90% with fasting glucose > or = 7.8 mM. In women, the corresponding percentages were lower: 26% and 60%, 32% versus 64% respectively. The major increase in cardiovascular risk factors would appear to occur at 6.1 mM, for men, whereas the increase in the combination of risk factors was at the more conservative cut-off of 7.0 mM.

Adult↗
PubMed1996

Liver function tests in normal pregnancy: a prospective study of 103 pregnant women and 103 matched controls.

Except for increased serum alkaline phosphatase (AP) levels, the changes in liver function test (LFT) values during normal pregnancy have not been clearly established, mainly because most studies do not include matched controls. We therefore measured the serum values of routine liver tests including 5'-nucleotidase and total bile acids in 103 healthy pregnant women (first trimester, n = 34; second trimester, n = 36; third trimester, n = 33) and in 103 age-matched controls not receiving oral contraception. Fasting blood samples were taken. Because of hemodilution, serum albumin levels were significantly lower during all trimesters. As expected, AP activity was significantly higher in the third trimester. Serum aspartate transaminase (AST) activity and total bile acid (TBA) concentrations did not differ between pregnant and nonpregnant women. Serum alanine transaminase (ALT) activity was slightly higher in the second-trimester pregnant women than in controls (6.8 +/- 4.5 vs. 8.2 +/- 5.8, P = .04), although all values remained within normal limits. In pregnant women, total and free bilirubin concentrations were significantly lower during all three trimesters, as was conjugated bilirubin during the second and third trimesters. Serum gamma-glutamyl transpeptidase (GGT) activity was significantly lower in the second and third trimesters. Serum 5'-nucleotidase activity was slightly but significantly higher in the second and third trimesters. The knowledge of these results is useful for the interpretation of LFT values and the management of liver diseases during pregnancy.

5'-Nucleotidase↗
PubMed1996

Relations among night work, dietary habits, biological measure, and health status.

A cross-sectional study was conducted to investigate dietary intake, behavioral habits, and clinical and metabolic differences in night workers compared to day workers and to evaluate the metabolic differences associated with diet and body habits that occur between these two groups. Dietary habits, biological parameters, and health status were collected in 1,200 night workers and in an equal number of day workers, matched for gender, age, and socioeconomic status. Our findings demonstrated that night workers had poorer dietary habits and metabolic profile compared to day workers with a similar overall health status. These differences were associated with a higher prevalence of some cardiovascular risk factors such as smoking and obesity.

Journal Article↗
PubMed1995

[Study of blood lead levels in a population of 616 subjects from the regions: Centre and Pays de Loire].

OBJECTIVES: Low-lead level exposure has been associated with harmful health effects. Blood lead is the most widely used marker of exposure. In this work, our purpose was to evaluate the present level of blood lead in a group of 616 subjects from the general population living in two regions of France: Centre and Pays de Loire. METHODS: Subjects were randomly included in the study. Blood lead was measured by inductively coupled plasma mass spectrometry which is the most sensitive and specific method. RESULTS: The mean blood lead concentration of the population studied ranged from 46.7 +/- 20.5 micrograms/l in the 6-10 year old to 86.6 +/- 42.4 micrograms/l in the 50-66 year old subjects. From 385 children under 13 years old, 5 had blood lead higher than 100 micrograms/l, the maximum acceptable level recommended by the American Centers for Disease Control. Women had lower blood lead values than men and their levels remained unchanged until 50 years but increased beyond this age. CONCLUSION: Mean lead levels were low in this French population. There is however risk of higher levels in persons living in old housing.

Adolescent↗
PubMed1995

Haemoccult test properties according to type and number of positive slides in mass screening for colorectal cancer.

Despite encouraging results from recent studies, there is still no consensus to undertake mass screening using the Haemoccult test in the general population. The success of mass screening for colorectal cancer depends among other things on Haemoccult test properties. In on-going screening programmes, the Haemoccult test consists of six slides and a test is considered positive if at least one slide is coloured. The aim of this work was to study the influence of the type and number of positive slides on the Haemoccult test's positive predictive value and characteristics of screened lesions. This work focuses on 63,958 first tests in a mass screening programme in Calvados (France) among people aged 45-74 years. There was a linear relation between the positive predictive value for cancer or an adenoma larger than 1 cm and the number of positive slides (P < 10(-4)). The positive predictive value for cancer or large adenoma was significantly higher when 4-6 slides were positive (44.3%) than when only 1-3 were positive (19.1%) (P < 10(-4)). In this latter group, the subjects in whom tumours were detected were younger and had significantly less extensive cancers. Borderline tests (no slides positive and at least one slide with a blue coloration confined to the edges) had a positive predictive value for cancer or an adenoma larger than 1 cm no different to that of tests with 1-3 positive slides. Subjects with borderline results were markedly younger than the others and had less extensive cancers and rectal localisation more often than the others. Our results suggest that (1) increasing the number of positive slides required to declare a test positive leads to an increase in the positive predictive value but is not to be recommended because of the sensitivity of the test and (2) considering borderline Haemoccult tests as positive in on-going and future mass screening campaigns would allow an increase in the sensitivity of the test, especially for rectal cancer and low extensive tumours without any decrease in its positive predictive value.

Aged↗
PubMed1995

Immunogenetic determinants and prediction of IDDM in French schoolchildren.

Islet cell antibodies (ICAs) are predictive markers of the disease in first-degree relatives of patients with insulin-dependent diabetes mellitus (IDDM). The large majority of newly diagnosed cases, however, will develop in children with no family history of diabetes. In France, the risk for development of IDDM up to the age of 20 years is 60 times higher in first-degree relatives than in the general population. The aim of this study was to test whether data collected in the first-degree relatives of IDDM patients could be transferred to children for the prediction of overt diabetes. A large population-based cohort of French school-aged children (n = 13,380; ages 6-17 years) were screened for ICAs, and results were compared with those of 1,185 first-degree relatives of IDDM patients. ICA prevalence rates were significantly different in the two populations (5.5% vs. 1.5%; P < 0.0001), with a significantly higher proportion of high ICA titers in first-degree relatives (37%) than in schoolchildren (14%) (P = 0.0005). ICA titers remained remarkably stable in children over 4 years. Insulin autoantibodies (IAAs) were found in 3.4 and 15.4% of ICA+ children and first-degree relatives, respectively. Susceptibility alleles at the human leukocyte antigen (HLA)-DQB1 locus were observed significantly more frequently in children in whom ICA titers > or = 20 Juvenile Diabetes Foundation units (JDF U) were found on two separate occasions (67%) than in ICA- children (52%) (P = 0.05). Five subjects developed overt diabetes during follow-up. ICA titers of > 20 JDF U were found in all of them on the first sample and at follow-up.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Assessment and standardization of the body mass index in French males aged 18-59 years].

This study of the corpulence of 54,360 French men aged from 18 to 59 years assessed the existence of a biological constant between height and weight. We observed a linear relation that links height to the mean weights corresponding to a fixed height. This new relationship informs us on the excess or the deficit of weight of each man and allows comparisons between body mass index in men, even if they have different heights or ages.

Adult↗
PubMed1995

[Prevalence of longitudinal melanonychia in the white population].

OBJECTIVES: The aim of this study was to determine the prevalence of longitudinal melanonychia (ML) in white subjects in order to obtain epidemiological data suggesting management strategies. PATIENTS AND METHODS: We included 99 hospitalized patients in this study, all were examined by a dermatologist. Another 4,400 healthy subjects were examined by a general practitioner. Criteria retained were age, sex, the presence or not of ML, the localization, number of bands, intensity of the coloration and size. RESULTS: The prevalence of ML was 12.6 +/- 3.4 p. 100 (CI 5.9-19.3) and 1.4 +/- 0.18 p. 100 (CI 1.3-1.75) respectively in the 99 and 4,400 subjects. The percentage of subjects increased progressively with age, particularly after 45 years and reached a peak between 56 and 65 years. The age distribution was identical. The most frequent localization was the thumb, followed by the great toe and the index. None of the ML observed had a clinical presentation suggestive of melanoma and no biopsies were taken. CONCLUSION: The frequency of melanonychia is thus higher in this series than that reported by previous studies where less than 1 p. 100 of the subjects had melanonychia. It was highest between the ages of 45 and 65 years. These results should be used when counselling patients and proposing systematic exeresis of ML above the age of 45 years.

Adolescent↗
PubMed1994

[Reference values of lipoprotein(a) in a French population].

OBJECTIVES: The aim of this work is to study the effect of different biological factors that could affect Lp(a) level in a presumably healthy population and to establish reference limits. METHODS: We selected 723 subjects (367 men and 356 women) for the age interval 4 to 64 years for evaluation. RESULTS: The distribution of Lp(a) is not Gaussian; 50.5% of subjects had Lp(a) concentrations under 0.10 g/l and the value for the 75th percentile was 0.27 g/l and 0.57 g/l for the 90th percentile. No relationship was observed between Lp(a) concentration and cholesterolaemia, triglyceridaemia, glycaemia, inflammatory proteins (orosomucoide and CRP), overweight, tobacco consumption and oral contraceptive use. The menopause state in women was a factor correlated with increased Lp(a) but this increase was not significant. Moreover, alcohol consumption (more than 44 g per day in men and more than 22 g per day in women) was associated with lower Lp(a) values. Among familial cardiovascular risks, only paternal listing of hypertension was associated with Lp(a) concentration in men. CONCLUSION: The measurement of Lp(a) in a young subject could be used as a genetic marker of cardiovascular risk associated with abnormal lipid metabolism and thrombosis phenomena.

Adolescent↗