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Biomedical subjects

M P Hermans

Publications and source records attributed to M P Hermans.

At least 19 recordsLinked to original sources
PubMed2006

The MTHFR CT polymorphism confers a high risk for stroke in both homozygous and heterozygous T allele carriers with Type 2 diabetes.

OBJECTIVE: Individuals with Type 2 diabetes are at increased risk of stroke. Plasma homocysteine (tHcy) is an independent risk factor for cardiovascular (CV) disease. The methylene-tetrahydrofolate reductase (MTHFR) gene polymorphism (thermolabile variant C(677)T) is associated with CV risk, partly as a result of increased Hcy, especially in homozygous subjects. AIM: To relate the occurrence of the MTHFR polymorphism with stroke prevalence by examining allelic frequency and genotype distribution in 165 subjects with Type 2 diabetes studied for the presence of thermolabile C(677)T MTHFR mutation. RESULTS: Mean age was 67.7 years, and tHcy 18.2 micromol/l. T allele frequency was 38.5%. MTHFR genotypes were: normal (CC) 40%; heterozygous (CT) 43%; homozygous (TT) 17%. Serum levels of folic acid and B12 vitamin were within normal limits. Stroke prevalence was 14%. Sixty-four per cent of stroke-free subjects had the normal C allele vs. 46% in stroke subjects. The frequencies of genotypes (CC-CT-TT) were (%): 44-41-15 in stroke-free vs. 17-57-26 in stroke patients. Coronary (CAD) and peripheral artery disease (PAD) were common in all groups, with no differences according to genotypes. Stroke prevalence was markedly higher in genotypes CT and TT (18 and 21%) compared with CC (6%). Mean tHcy levels were higher in TT subjects. CONCLUSION: The allelic frequency of C(677)T MTHFR mutation in Type 2 diabetes subjects with stroke is markedly different from that of subjects without stroke. Genotypic characteristics suggest that C(677)T MTHFR mutation confers a higher risk for stroke to both homozygous and heterozygous T allele carriers that cannot be ascribed solely to raised tHcy and/or lower folate status in CT subjects, nor to phenotypic expression of conventional risk factors for stroke. The impact of the MTHFR polymorphism on stroke may result from T allele-linked deleterious effects, or C allele-linked protection. Confirmatory studies are warranted, as this cohort was not randomly selected, and a type 1 error cannot be ruled out.

Aged↗
PubMed2005

Prospective screening for biopsy proven coeliac disease, autoimmunity and malabsorption markers in Belgian subjects with Type 1 diabetes.

AIMS: To determine prospectively the prevalence of biopsy proven coeliac disease (CD) in an adult Type 1 diabetic population from Belgium with regards to associated auto-immunity and malabsorption. METHODS AND RESULTS: Determination in 400 Type 1 diabetic patients of serum anti-endomysial and/or anti-transglutaminase auto-antibodies. All subjects with abnormal serology underwent an intestinal biopsy. Ten patients (2.5%) had positive antibodies. Diagnosis of CD was confirmed by an intestinal biopsy. Eight patients were symptom-free, although laboratory findings suggesting malabsorption were prominent in the presence of CD [microcytic anaemia, iron and folate deficiencies, low levels of 25(OH)vitamin D3, calcium and cholesterol]. Other auto-immune conditions, especially vitiligo, were found in patients with CD. CONCLUSIONS: Asymptomatic coeliac disease occurs frequently in adult Type 1 diabetic patients, and is often associated with subclinical malabsorption. Screening should be part of routine evaluation, to implement life-long dietary gluten avoidance.

Adolescent↗
PubMed2004

C677T methylene-tetrahydrofolate reductase mutation in type 2 diabetic patients with and without hyperhomocysteinaemia.

OBJECTIVE: The aim of the study was to determine the prevalence of the C677T mutation in a cohort of type 2 diabetic patients with and without elevated total plasma homocysteine (tHcy). METHODS: 80 type 2 diabetic patients with hyperhomocysteinaemia (group 1, tHcy: 21.3 +/- 6.7 micromol/L) and 50 subjects with normal levels (group 2, tHcy 11.2 +/- 2.3 micromol/L) were studied. C677T mutation was assessed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). RESULTS: Homozygosity was present in 23% of patients in group 1 and 8% in group 2 (P<0.02). No significant difference in heterozygosity frequency was observed between patients with and without hyperhomocysteinaemia. T allele frequency was 0.43 in group 1 and 0.35 in group 2. CONCLUSION: C677T mutation is frequent in diabetic patients with hyperhomocysteinaemia and could contribute, besides non genetic factors, to increased levels of tHcy.

Aged↗
PubMed2003

Comparative performance of serum cystatin-c versus serum creatinine in diabetic subjects.

OBJECTIVE: Serum cystatin-C, a protein with constant production rate, undergoes glomerular filtration. Cystatin-C is a candidate surrogate marker, allegedly superior to serum creatinine, for estimating glomerular filtration rate, due to its high correlation with absolute measurement of the latter. The aim of this study was to assess from intra- and inter-subject variability the performance of cystatin-C in a cohort of diabetic patients spanning a wide range of kidney function and to compare it to that of serum creatinine. RESEARCH DESIGN AND METHODS: 98 consecutive diabetic in-patients (45 type 1 and 53 type 2) were included. Mean age was 53 +/- 15 years (1SD). Creatinine clearance was 98 ml/min (median; range: 16-244). We used the discriminant ratio (DR) methodology to compare the performance of serum cystatin-C vs. that of creatinine to segregate subjects according to their glomerular filtration rate. RESULTS: Serum creatinine values on day 1 and 2 were 1.10 +/- 0.76 and 1.07 +/- 0.89 mg/dl and concentrations of cystatin-C were 1.10 +/- 0.60 and 1.06 +/- 0.63 mg/L. A close linear relationship was observed between means of duplicates for creatinine and cystatin-C (Pearson product-moment correlation 0.92). DR was obtained from the ratio of the underlying between-subject to the within-subject standard deviations. DR values were 5.23 for creatinine and 8.82 for cystatin-C (P<0.0001), implying superior discriminating ability for cystatin-C. Once adjusted for attenuation, measured Pearson product-moment correlation rose from 0.92 to 0.97. The DR methodology allowed for deriving an unbiased linear regression equation between methods, with slope and intercept at 0.79 and 0.23, respectively. CONCLUSIONS: Serum cystatin-C better discriminates among a population of type 1 and 2 diabetic patients with regard to their estimated glomerular filtration rate when compared with conventional serum creatinine measurement.

Blood Pressure↗
PubMed2003

Hyperadiponectinaemia in anorexia nervosa.

OBJECTIVE: Adiponectin (ApN) is a fat-derived hormone that enhances insulin sensitivity, controls body weight, prevents atherosclerosis and negatively regulates haematopoiesis and immune functions. In contrast to many proteins secreted by adipose tissue, the circulating level of ApN falls in obesity and insulin resistance states. The influence of starvation-induced depletion of fat stores on ApN concentrations is yet unknown. We therefore investigated plasma ApN in anorexia nervosa (AN). PATIENTS AND DESIGN: We measured plasma ApN in 26 female anorectic patients and examined its relationships to several anthropometric or metabolic parameters. Twenty-four age-matched healthy female controls (C) were also studied. RESULTS: Body mass index (BMI) and fat mass were markedly decreased in AN. However, plasma ApN levels were 30% higher in anorectic than in control subjects (P < 0.01), while a reverse pattern was observed for leptin concentrations. When normalized for fatness, ApN values almost doubled in AN. ApN levels were negatively correlated with BMI and fat mass (P < 0.05 in the combined population, AN + C). Insulin sensitivity tended to be 40% higher in AN (n = 7) than in C (n = 12) subjects, and plasma ApN levels were positively correlated with insulin sensitivity (P < 0.05 in AN + C subgroups). Total and low density lipoprotein (LDL)-cholesterol were higher, or tended to be higher, in AN, but there were no correlations between plasma ApN and plasma lipids. By contrast, ApN was related to the lipid profile, in a manner consistent with its antiatherogenic role, in healthy controls [i.e. negatively correlated with triglycerides, total and LDL-cholesterol and total/high density lipoprotein (HDL) cholesterol; P < 0.05 or less for each parameter]. In a multiple regression analysis, BMI and insulin sensitivity in AN were independent determinants for ApN levels, explaining up to approximately 80% of the variance in this measure. CONCLUSIONS: Plasma adiponectin levels are increased in anorexia nervosa. This may, at least in part, be due to the lack of negative feedback exerted by fat mass on adiponectin production and/or to enhanced insulin sensitivity. We speculate that hyperadiponectinaemia could, in turn, contribute to maintain a state of enhanced insulin sensitivity and possibly exacerbate haematological and infectious complications of anorexia nervosa.

Adiponectin↗
PubMed2002

Clinical expression and insulin sensitivity in type 2 diabetic patients with heterozygous mutations for haemochromatosis.

BACKGROUND: Elevated iron metabolism indices as well as liver enzymes abnormalities have been reported in type 2 diabetic patients. The aim of this study was to determine the clinical and biological characteristics of overweight or obese type 2 diabetic subjects, with and without heterozygosity for HFE gene mutation (C282Y or H63D). We also assessed their insulin sensitivity and B cell function. METHODS: 90 patients (age and diabetes duration: 61 +/- 11 and 12 +/- 8 years [mean +/- 1 SD]) were included. BMI was 32 +/- 6 kg/m(2). HbA(1c) was 8.9 +/- 1.8%. HFE genotyping was performed by PCR and restriction enzyme cleavage. Insulin sensitivity and B cell function were measured by the Homeostasis Model Assessment (HOMA). RESULTS: Heterozygosity for C282Y (wt/C282Y) or H63D (wt/H63D) allele was found in 11 and 12 subjects respectively. There were no major differences in clinical status and iron parameters according to the single allelic presence of C282Y or H63D. However, systolic blood pressure [BP] was lower when such mutation was present. Insulin sensitivity and B cell function (HOMA) were comparable. When the cohort was divided according to gender, we found higher serum iron in females with than in those without HFE mutation (91 +/- 27 vs 73 +/- 25 microgram/dl;P=0.049), while a transferrin saturation index above 45% was observed in 36% of females with a mutation (vs 7% in wt/wt;P=0.06). When analysis was performed according to the presence of each particular mutation, we observed a transferrin saturation index higher than 45% in 60% of wt/C282Y patients vs 21% in the wt/wt group (P=0.008). A significantly lower BP was also identified in wt/C282Y patients. Cholesterol-HDL was 38 +/- 11 vs 46 +/- 12 mg/dl in wt/C282Y and wt/wt subjects, respectively (P=0.045). There were no differences in iron status, BP or lipids between wt/wt and wt/H63D subjects. CONCLUSION: Type 2 diabetic patients, in particular females, with mono-allelic C282Y mutation, had slightly increased iron parameters. Systolic BP and cholesterol-HDL were also lower in wt/C282Y subjects. No difference in insulin sensitivity or B cell function was observed in the presence of mono-allelic HFE mutations.

Adult↗
PubMed2001

Erectile dysfunction and lower androgenicity in type 1 diabetic patients.

OBJECTIVE: To analyse the clinical characteristics and relevant hormonal profile in type 1 diabetic patients with and without ED. MATERIAL AND METHODS: Fifty one type 1 diabetic patients were studied. ED was assessed by direct interview. Chronic diabetic complications, smoking and alcohol status as well as current use of medications were recorded. Hormonal profile consisted of plasma LH, FSH, prolactin, androstenedione (Delta(4)), dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEA-S), free testosterone (FT), estradiol (E(2)), sex hormone binding globulin (SHBG), dihydrotestosterone (DHT), cortisol, TSH and free thyroxine (FT(4)). RESULTS: ED was present in 24 patients (47%) (group 1), who were older (P<0.001), had a longer diabetes duration (P<0.001) and a higher systolic blood pressure (P=0.017) when compared to the subjects who did not complain (group 2). ED was positively correlated to all diabetes-related complications (P<0.02). Antidepressive drug(s) were more frequent in group 1 (P=0.007), as well as prokinetics (P=0.043) and ACE-inhibitors (P=0.010). HbA(1)c was comparable. Patients with ED had lower levels of Delta(4) (P=0.003), DHEA (P<0.001), DHEA-S (P=0.002), FT (P=0.08) while SHBG (P=0.010) and LH (P=0.022) were higher compared to group 2. Multiple logistic regression analysis showed an independent association of ED with Delta(4) (P=0.016), DHEA-S (P=0.037), SHBG (P=0.001) and insulin dose (P=0.025). There was no significant difference for all other measured hormones. CONCLUSION: ED is impressively prevalent in type 1 diabetes and is associated with age, diabetes duration, chronic complications and decreased androgens.

Age Factors↗
PubMed2001

Micro- and macrovascular complications and hyperhomocysteinaemia in type 1 diabetic patients.

OBJECTIVE: To determine the range of plasma homocysteine values in a cohort of type 1 diabetic subjects and to analyse the relationship between homocysteine levels and chronic degenerative complications. MATERIAL AND METHODS: 71 type 1 diabetic inpatients admitted for poor glycaemic control and/or treatment of complications, especially macroangiopathic, were included in this study. Chronic diabetic complications, smoking prevalence, as well as current use of drugs were recorded, alongside fasting plasma homocysteine. RESULTS: Age and diabetes duration were 51 (34-63) and 23 (13-32) years respectively (median [percentile 25-75]). HbA(1)c was 9.3% (8.2-10.5). Homocysteine was 9.2 (7.1-13.6) micromol/l, and 17% of patients had elevated homocysteinaemia on the basis of a laboratory cutoff value of 15 micromol/l. Folic acid and vitamin B(12) levels were within the normal range. Univariate statistical analysis showed a significant positive association between homocysteine and age (P<0.001), diabetes duration (P<0.001), systolic blood pressure (P<0.001), plasma creatinine (P<0.001), cholesterol/HDL-C (P=0.021) as well as with retinopathy (P=0.016) and all complications (P<0.001), and a negative correlation with folic acid (P=0.004) and creatinine clearance (P<0.001). Using a multiple regression analysis taking into account major variables, we confirmed an independent association of homocysteine with age (P=0.003), creatinine (P<0.001) and folic acid (P=0.014), but not with vascular complications. CONCLUSIONS: Increased homocysteine is present in 17% of a limited group of poorly controlled type 1 diabetic patients, and is associated with age, creatinine and folic acid levels. In this type 1 population, there was no independent correlation of homocysteine with vascular complications, in particular macroangiopathy.

Adult↗
PubMed2000

Hyperhomocysteinemia in type 2 diabetes: relationship to macroangiopathy, nephropathy, and insulin resistance.

OBJECTIVE: The aim of this study was to determine the distribution of plasma total homocysteine (tHcy) concentrations in type 2 diabetic patients and to assess whether high tHcy values were related to chronic complications (particularly macroangiopathy and nephropathy) and/or the degree of insulin resistance. RESEARCH DESIGN AND METHODS: Fasting tHcy levels were measured in 122 type 2 diabetic patients in whom the presence of chronic complications (e.g., macroangiopathy, microalbuminuria, macroproteinuria, decreased creatinine clearance, hypertension, retinopathy, and neuropathy) was recorded alongside an assessment of insulin resistance by the homeostasis model assessment (HOMA). RESULTS: We found that 31% of the cohort (group 1) had raised tHcy (mean +/- 1 SD) values (20.8 +/- 5.1 micromol/l), whereas 69% (group 2) had normal values (10.2 +/- 2.0 micromol/l). The prevalence of macroangiopathy was higher in group 1 than in group 2 subjects (70 vs. 42%, P < 0.01); the prevalence of coronary artery disease was particularly higher in group 1 (46 vs. 21%, P < 0.02). The prevalence of impaired renal function, evidenced by decreased creatinine clearance, was higher in group 1 (32 vs. 10%, P < 0.005). Other clinical and biological characteristics of both groups were comparable, although group 1 had lower levels of folic acid than group 2 (5.2 +/- 2.9 vs. 7.0 +/- 3.4 ng/ml, P < 0.01). No differences were found for microalbuminuria (33 vs. 31%), retinopathy (45 vs. 42%), or neuropathy (70 vs. 59%) between groups 1 and 2, respectively The degree of insulin resistance was similar in groups 1 and 2 (46 +/- 21 and 42 +/- 20% of HOMA-insulin sensitivity) as was the assessment of beta-cell function (63 +/- 28 and 65 +/- 46%, respectively). No differences in tHcy levels were found between subjects receiving metformin and those not receiving metformin. In contrast, the plasma tHcy level was higher in diabetic patients treated with fibrates (P = 0.0016). CONCLUSIONS: Elevated plasma tHcy levels in type 2 diabetes is associated with a higher prevalence of macroangiopathy and nephropathy when assessed from creatinine clearance indexes and is not associated with different degrees of insulin resistance.

Aged↗
PubMed1999

Comparison of insulin sensitivity tests across a range of glucose tolerance from normal to diabetes.

AIMS/HYPOTHESIS: Adequate comparison of the relative performance of insulin sensitivity tests is not yet available. We compared the discrimination of four insulin sensitivity tests, commonly used in vivo, across a range of glucose tolerance. METHODS: Normal (n = 7), impaired glucose tolerant (n = 8) and Type II (non-insulin-dependent) diabetic subjects (n = 9) had in random order two tests from the following: frequently sampled insulin-modified intravenous glucose tolerance test (FSIVGTT-MinMod); homeostasis model assessment (HOMA) and 2-h continuous infusion of glucose with model assessment (CIGMA) with immunoreactive or specific insulin; short insulin tolerance tests (ITT). The discriminatory power of tests was assessed by the ratio of the within-subject standard deviation to the underlying between-subject standard deviation (discriminant ratio - DR). The degree to which tests measured the same variable was assessed by comparing rank correlation with the maximum expected correlation given the imprecision of the tests. The unbiased lines of equivalence taking into account the precision of tests were constructed. RESULTS: Reciprocal fasting plasma insulin (FPI(-1)), HOMA %S and 2-h CIGMA %S, had similar DRs with ITT being less informative. The FSIVGTT-MinMod analysis was able to assess 13 out of 24 subjects and had a performance similar to ITT. Using specific rather than immunoreactive insulin for HOMA-CIGMA did not improve the DR. Reciprocal fasting plasma insulin FPI(-1), HOMA %S, 2-h CIGMA %S and S(I) FSIVGTT intercorrelated more than 90% of the expected rank correlation given the imprecision of the tests, but ITT gave only limited correlation. CONCLUSION/INTERPRETATION: The HOMA-CIGMA test with immunoreactive insulin provides similar information in distinguishing insulin sensitivity between subjects with normal glucose tolerance, those with impaired glucose tolerance and those with Type II diabetes as does FSIVGTT, whereas ITT is less informative.

Adult↗
PubMed1999

Frequency of glycogen storage disease type II in The Netherlands: implications for diagnosis and genetic counselling.

Glycogen storage disease type II (GSD H) is an autosomal recessive myopathy. Early and late-onset phenotypes are distinguished - infantile, juvenile and adult. Three mutations in the acid alpha-glucosidase gene are common in the Dutch patient population: IVS1(-13T-->G), 525delT and delexon18. 63% of Dutch GSD II patients carry one or two of these mutations, and the genotype-phenotype correlation is known. To determine the frequency of GSD II, we have screened an unselected sample of neonates for the occurrence of these three mutations. Based on the calculated carrier frequencies, the predicted frequency of the disease is 1 in 40000 divided by 1 in 138 000 for infantile GSD II and 1 in 57 000 for adult GSD II. This is about two to four times higher than previously suggested, which is a reason to become more familiar with the presentation of GSD II in its different clinical forms and to adjust the risk assessment for genetic counselling.

Alleles↗
PubMed1999

Glycaemic and blood pressure controls achieved in a cohort of 318 patients with type 2 diabetes.

The aim of the study was to evaluate the current antihyperglycaemic and antihypertensive treatment schemes as well as the quality of metabolic control and blood pressure in a population with type 2 diabetes, in view of the United Kingdom Prospective Diabetes Study (UKPDS) data. 318 patients were included. 44% were treated with metformin and/or sulfonylurea. 44% received insulin in monotherapy or combined with oral drugs. HbA1c was 8.0 (7.9-9.4)% (median; percentiles 25-75). Chronic neurological and vascular (micro- and macroangiopathy) complications were present in 21-43% of patients and were related to glycaemic control. (Un)treated hypertension was found in 59% of patients. Main treatments were ACE-inhibitors (40%), calcium channel antagonists and diuretics (20%) and/or beta-blockers (18%). Systolic and diastolic blood pressure were 147 +/- 22 and 86 +/- 12 mm/Hg (mean +/- 1 SD). In conclusion, overall glycaemic control of a type 2 diabetic population remains slightly unsatisfactory in view of the UKPDS recommendations. In contrast, blood pressure control was adequate.

Administration, Oral↗
PubMed1999

Comparison of tests of beta-cell function across a range of glucose tolerance from normal to diabetes.

Adequate comparisons of the relative performance of different tests of beta-cell function are not available. We compared discrimination of commonly used in vivo tests of beta-cell function across a range of glucose tolerance in seven subjects with normal glucose tolerance (NGT), eight subjects with impaired glucose tolerance (IGT), and nine subjects with type 2 diabetes. In random order, each subject underwent two of each of the following tests: 1) frequently sampled 0.3-g/kg intravenous glucose tolerance test (FSIVGTT) with MinMod analysis; 2) homeostasis model assessment (HOMA) from three samples at 5-min intervals with a model incorporating immunoreactive or specific insulin measurements; and 3) continuous infusion of 180 mg x min(-1) x m(-2) glucose with model assessment (CIGMA) of three samples at 50, 55, and 60 min (1-h CIGMA) and at 110, 115, and 120 min (2-h CIGMA). The discrimination of each test was assessed by the ratio of the within-subject SD to the underlying between-subject SD, the discriminant ratio (DR). The degree to which tests measured the same physiological variable was assessed using Pearson's correlation coefficient adjusted for attenuation due to test imprecision. An unbiased line of equivalence, taking into account the imprecision of both tests, was used to compare results. Beta-cell function assessed from HOMA and beta-cell function assessed from CIGMA (CIGMA%beta) (using immunoreactive insulin) had higher DRs than first-phase intravenous glucose tolerance test-derived incremental insulin peak, area, insulin-to-glucose index, and acute insulin response to glucose from FSIVGTT-MinMod. CIGMA%beta (immunoreactive insulin) had the highest DR. FSIVGTT-derived first-phase insulin response tests correlated only moderately with HOMA and CIGMA. Using specific rather than immunoreactive insulin for HOMA and CIGMA did not improve discriminatory power. Simple tests such as HOMA and CIGMA, using immunoreactive insulin, offer better beta-cell function discrimination across subjects with NGT, IGT, and type 2 diabetes than measurements derived from FSIVGTT first-phase insulin response.

Analysis of Variance↗