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Biomedical subjects

M Hanefeld

Publications and source records attributed to M Hanefeld.

At least 19 recordsLinked to original sources
PubMed2000

Impaired glucose tolerance (IGT) is not associated with disturbed homocysteine metabolism.

Elevated plasma total homocysteine (tHcy) has been suggested to be an additional risk factor for cardiovascular disease in subjects with impaired glucose tolerance (IGT) and Type 2 diabetes (T2D). In order to investigate whether an insulin resistant/chronic hyperinsulinemic situation in male diabetic and prediabetic subjects directly influences the tHcy metabolism, fasting tHcy and post-methionine load tHcy plasma levels (PML-tHcy) were determined in 15 men with IGT, 13 men with newly diagnosed T2D, and 16 normoglycemic controls (NGT). Fasting tHcy (IGT, 13.1 +/- 4.6; T2D, 12.8 +/- 4.0; NGT, 10.7 +/- 4.4 micromol/L) and PML-tHcy (IGT, 46.5 +/-17.39; T2D, 41.1 +/- 6.8; NGT, 38.0 +/- 9.7 micromol/L) showed no differences between the groups. Fasting tHcy and PML-tHcy correlated with fasting proinsulin (r = 0.395, p < 0.05; r = 0.386, p< 0.05) and creatinine (r = 0.489, p < 0.01; r = 0.339, p < 0.05), resp. Multiple regression analysis showed only a relationship between fasting tHcy and creatinine. No relationships have been found between fasting tHcy and PML-tHcy, resp., and indicators of an insulin resistant state, e.g., insulin and proinsulin, as well as serum cobalamin and folate concentrations. In conclusion, our data suggest that the degree of glucose intolerance has no direct impact on the metabolism of homocysteine. However, tHcy levels tend to be elevated with the development of nephropathy, indicating an association between tHcy and renal function in these subjects.

Blood Glucose↗
PubMed2000

Post-challenge hyperglycaemia relates more strongly than fasting hyperglycaemia with carotid intima-media thickness: the RIAD Study. Risk Factors in Impaired Glucose Tolerance for Atherosclerosis and Diabetes.

AIMS: Only scarce information exists on the distribution and atherosclerosis risk in different types of hyperglycaemia at diabetes detection. This study aimed to analyse the occurrence of isolated fasting (IFH), isolated post-challenge (IPH) and combined hyperglycaemia (FH/PH) among subjects detected to have diabetes and the association of these types of hyperglycaemia with cardiovascular risk factors and carotid intima-media thickness (IMT). METHODS: A total of 785 middle-aged subjects of the Risk Factors in Impaired Glucose Tolerance (IGT) for Atherosclerosis and Diabetes (RIAD) study underwent a 75-g oral glucose tolerance test and examination of various atherosclerosis risk factors. IMT was measured by B-mode ultrasound. RESULTS: One hundred and nineteen (15.2%) asymptomatic diabetic subjects were detected: of these, 35.3% with IFH, 26% with IPH and 38.7% with FH/PH. The level of risk factors was higher in diabetic vs. non-diabetic subjects. HbA1c and cardiovascular risk factors were in the same range for IFH and IPH except for active plasminogen activator inhibitor (PAI)-1 which was significantly higher in IFH. A higher risk burden was found in the FH/PH group vs. both IFH and IPH. IMT was as follows: non-diabetic subjects 0.85 +/- 0.18 mm, IFH 0.91 +/- 0.20 mm, IPH 0.94 +/- 0.18 mm, FH/PH 0.98 +/- 0.17 mm (P < 0.05 vs. non-diabetes). 2 h post-challenge glucose (2hPG) correlated more closely (r = 0.23, P < 0.001) to IMT than fasting plasma glucose (FPG) (r = 0.14, P = 0.004). The importance of 2hPG was confirmed by the direct comparison of FPG and 2hPG in a three dimensional analysis. A significant increase of IMT was only observed in the subgroups with abnormal post-challenge hyperglycaemia for both combinations with normal FPG and IFG. FPG category did not significantly add to IMT in either group of post-challenge hyperglycaemia. Regression analysis in the whole sample revealed 2hPG but not FPG as a significant determinant of IMT. Further significant risk factors were age, male sex, total cholesterol, HDL-cholesterol and hypertension. CONCLUSIONS: The RIAD study population at high risk for Type 2 diabetes mellitus, post-challenge hyperglycaemia was found to relate more strongly than fasting hyperglycaemia with carotid IMT.

Adult↗
PubMed2000

Prevalence and atherosclerosis risk in different types of non-diabetic hyperglycemia. Is mild hyperglycemia an underestimated evil?

So far little is known about the importance of different types of non-diabetic hyperglycemia for the development of macrovascular disease. The aim of this work was to examine the intima-media thickness (IMT) of the common carotid artery (CCA), a well-accepted marker of atherosclerosis, as well as various risk factors for atherosclerosis in non-diabetic subjects with isolated fasting (IFH; n=67), isolated postchallenge (IPH; n=82) and combined hyperglycemia (CH; n=88) in comparison to normoglycemic (NG; n=265) controls. Subjects were participants of the RIAD study (Risk Factors in IGT for Atherosclerosis and Diabetes). IMT in the IPH (IMTmean: 0.89+/-0.02 mm; IMTmax: 1.01+/-0.02 mm; mean+/-SEM) and CH group (IMTmean: 0.91+/-0.02 mm; IMTmax: 1.03+/-0.02 mm) was significantly increased vs. the NG (IMTmean: 0.82+/-0.01 mm; IMTmax: 0.94+/-0.01 mm) and IFH group (IMTmean: 0.81+/-0.02 mm; IMTmax: 0.90+/-0.03 mm). IMT of the IFH group was similar to the normoglycemic controls. Subjects in the first and second tertile for postchallenge plasma glucose have similar carotid IMT irrespective of the level of fasting plasma glucose. The individuals of the third tertile for 2 h plasma glucose, whether in the first, second or third tertile of fasting plasma glucose, showed the same carotid IMT, which was significantly higher than all other groups, except for the one with lowest tertile for fasting and postchallenge plasma glucose. Except for total cholesterol and von Willebrand factor the levels of all other risk parameters were significantly higher in the hyperglycemic groups in comparison to the normoglycemic controls. Among the hyperglycemic subjects the CH group was at the highest risk for atherosclerosis with significantly increased levels of plasma triglycerides, fibrinogen, PAI-1, albuminuria, HDL-triglycerides, free fatty acids, insulin and proinsulin, and significantly reduced HDL-cholesterol in comparison to the normoglycemic controls. In summary, postchallenge hyperglycemia within the non-diabetic range is associated with atherosclerosis, as measured by the increased intima-media thickness of the common carotid artery. Furthermore, cardiovascular risk factors are significantly raised in all types of non-diabetic hyperglycemia.

Albuminuria↗
PubMed2000

Metabolic diseases and their possible link to risk indicators of periodontitis.

BACKGROUND: During the last few years, risk assessment has become one of the main topics of periodontal research. Therefore, the aim of this study was to determine whether a predisposition to metabolic disorders such as diabetes mellitus (in the absence of diagnosed diabetic disease) or hyperlipidemia may be risk indicators for periodontitis. METHODS: One hundred patients ranging in age from 40 to 70 years were examined. The patients were classified as having impaired glucose tolerance (IGT) but no manifest diabetes (56 patients), hyperlipidemia (17 patients, HL), or normal metabolic status (27 control patients). Probing depth (PD), attachment level (AL), plaque index (PI), and gingival bleeding on probing (BOP) were recorded. Serum antibody titers (SAT) to A. actinomycetemcomitans (A.a.), P. intermedia (P.i.), and P. gingivalis (P.g.) were determined by enzyme-linked immunosorbent assay (ELISA). Pooled subgingival plaque samples were analyzed using indirect immunofluorescence to detect the same organisms. In addition, respiratory burst activity of peripheral polymorphonuclear leukocytes (PMN) was evaluated by chemiluminescence (CL). RESULTS: No significant differences were observed between the IGT group and normal controls in the following parameters: 1) percentage of sites exhibiting BOP; 2) mean PI; 3) mean PD and AL; 4) percentage of periodontal microorganisms; and 5) increased SAT. The IGT probands exhibited a significantly higher mean serum level of triglycerides, as well as higher formyl-methionyl-leucyl-phenylalanine (FMLP)-stimulated PMN chemiluminescence than the control group. Patients with hyperlipidemia (HL) showed a significantly higher number of sextants with increased PD (73.4%) than the control group (50.6%). Similar results were obtained when comparing the percentage of all sites with increased PD (HL = 16.7%, control 12.3%). The mean FMLP-stimulated CL in patients with hyperlipidemia was significantly higher than the control group. When looking at all patients, there was a small but statistically significant correlation between PD and lipid levels. In addition, a significant correlation was observed between lipid serum levels and the FMLP-stimulated chemiluminescence. CONCLUSIONS: These findings suggest that abnormal glucose tolerance, which is a predisposing factor for diabetes mellitus, does not appear to be a risk indicator for periodontal disease. On the other hand, impaired lipid metabolism does seem to be a risk indicator for periodontitis.

Adult↗
PubMed2000

Postchallenge plasma glucose and glycemic spikes are more strongly associated with atherosclerosis than fasting glucose or HbA1c level.

OBJECTIVE: To observe the relationship of fasting plasma glucose (FPG), postchallenge plasma glucose (PG) (30, 60, 90, and 120 min during an oral glucose tolerance test [OGTT], as well as maximal PG during an OGTT, postchallenge glucose spikes [PGS], and glucose under the OGTT curve), and HbA1c to intima-media thickness (IMT) as a marker of atherosclerosis. RESEARCH DESIGN AND METHODS: OGTT, ultrasound measurement of carotid IMT, and various atherosclerosis risk factors, such as family history of diabetes, obesity, and/or hyperlipoproteinemia, but without known diabetes, were analyzed in 582 individuals aged 40-70 years and at risk for type 2 diabetes. RESULTS: In univariate analysis, all examined glycemic parameters were significantly correlated to IMT. The 2-h postchallenge plasma glucose showed the strongest odds ratio (OR) of 1.88 (1.34-2.63) in relation to abnormal IMT. All PG variables, except for 30-min glucose in OGTT, showed a significant OR, whereas the OR for HbA1c and FPG was not significant. In logistic regression analysis, 2-h PG was identified as the strongest determinant of IMT from all glycemic parameters. The 2-h PG and PGS, but not FPG, were associated with a significant rise of IMT in tertiles of HbA1c. Glycemic parameters were strongly related to each other and to many atherosclerosis risk factors. In multivariate analysis including a variety of atherosclerosis risk factors, 2-h PG was a significant independent determinant of IMT. CONCLUSIONS: PG and PGS are more strongly associated with carotid IMT than FPG and HbA1c level and modify substantially the risk for atherosclerosis, estimated by HbA1c alone, in a cohort at risk for diabetes and in the early diabetes stage.

Adult↗
PubMed2000

Rapid and short-acting mealtime insulin secretion with nateglinide controls both prandial and mean glycemia.

OBJECTIVE: The objective of the study was to assess the efficacy and safety of four fixed doses of nateglinide compared with placebo in the treatment of patients with type 2 diabetes with focus on the prandial state. RESEARCH DESIGN AND METHODS: This randomized double-blind placebo-controlled multicenter study was conducted in 289 patients who received either nateglinide at doses of 30 mg (n = 51), 60 mg (n = 58), 120 mg (n = 63), or 180 mg (n = 57) or placebo (n = 60) before three main meals for 12 weeks. Levels of HbA1c, fasting plasma glucose (FPG), fructosamine, and plasma lipids were measured at predetermined intervals, and the effects of nateglinide on prandial glucose insulin, C-peptide, and triglyceride levels were measured after a liquid standard meal (Sustacal; Mead Johnson, Evansville, IN). Adverse events and hypoglycemic episodes were recorded. RESULTS: After a liquid meal challenge, nateglinide rapidly increased mealtime insulin levels within 30 min of drug intake and reduced mealtime glucose excursions without affecting triglyceride levels. At study end point, reduction of HbA1c levels was statistically significantly greater with nateglinide at doses of 60, 120, and 180 mg than placebo (-0.45, -0.62, and -0.64%, respectively; P<0.05). The mean level of FPG was significantly reduced versus placebo in the nateglinide 120-mg group only (-1.14 mmol/l P<0.01). Overall, nateglinide was well tolerated. CONCLUSIONS: This study demonstrated that nateglinide improves mealtime and mean glycemic control in a dose-dependent manner by restoring early insulin secretion phase. Nateglinide was well tolerated and is suitable for the treatment of patients with type 2 diabetes.

Adult↗
PubMed1999

[Prevalence of newly diagnosed type 2 diabetes, impaired glucose tolerance and abnormal fasting glucose in a high risk population. Data from the RIAD study using new diagnostic criteria for diabetes].

BACKGROUND AND OBJECTIVE: In 1997 the American Diabetes Association (ADA) introduced new criteria for the diagnosis of type 2 diabetes mellitus, reducing the upper limit of normal fasting blood sugar from 140 to 126 mg/dl. A level of between 110 and 126 < mg/dl (6.1-7.0 mmol/l) was added as a new category, "impaired fasting glucose" (IFG) as an at-risk factor. It was the aim of this study to determine what effect these new criteria will have on the prevalence of type 2 diabetes and other glucose tolerance stages in the German population. PATIENTS AND METHODS: The analysis was based on data collected in the "Risk-factors in IGT for atherosclerosis and diabetes" (RIAD) study. 1139 persons of an at-risk population group (aged 40-70 years) were investigated. Most of them were relatives of diabetics and/or themselves had obesity and/or dyslipidaemia. All known diabetics were excluded. All subjects underwent an oral glucose test with 75 g glucose, and plasma glucose values were used for classifying them into different glucose tolerance stages. RESULTS: According to the new ADA criteria, confirmed by WHO in 1998, the prevalence of type 2 diabetes mellitus was shifted from 11% to 15.1%, that of IGT from 28.8% to 26.2%. An impaired fasting glucose was found in 27.1% of the population cohort, 9.2% of whom had 2-hour plasma glucose levels corresponding to the diabetes criteria. Men in the first age decade (40-49 years) had a 14% prevalence of previously undetected type 2 diabetes, double that in women. Hyperlipidaemia, hypertension and obesity were significantly more common in diabetics and persons with IGT than in normoglycaemic persons. CONCLUSIONS: The prevalence of previously unknown type 2 diabetes is very high in this at-risk part of the population. Using the criteria for impaired fasting glucose, 9.2% diabetics would remain undetected. We, therefore, support the recommendation that an oral glucose tolerance test be performed in those of the population aged over 45 years and in younger at-risk persons so that any indicated treatment can be initiated at the earliest. Measurement of fasting glucose is adequate in the population aged under 45 years not at special risk.

Adult↗
PubMed1999

[An unusual picture of insulinoma in type-2 diabetes mellitus and morbid obesity].

HISTORY AND CLINICAL FINDINGS: Marked hyperinsulinism was demonstrated in the course of an oral glucose tolerance test (oGTT) in a 63-year-old woman with severe obesity (height 1.59 m, body weight 123 kg, body-mass index 46.4 kg/m2). The diabetic metabolic state, first diagnosed 12 years ago, had been replaced by a low plasma glucose level: she often had attacks of ravenous hunger. A reducing diet of 800 kcal had not been tolerated. She had not had any syncopes. She had continually gained weight since puberty, but her weight had remained relatively constant for the past 5 years during which she had been treated with L-thyroxine for a diffuse goitre (stage II). INVESTIGATIONS: In the course of an oGTT (75 g glucose) the basal insulin concentration (146 pmol/l) had risen to 1663 pmol/l at 30 min. The basal proinsulin level was 50 times normal (66 pmol/l vs. 1.418 pmol/l), while the initial plasma glucose level had fallen from 4.3 mmol/l to 3.8 mmol/l. Spiral computed tomography of the pancreas showed a 3 x 2.5 cm mass in the region of the tail of the pancreas. TREATMENT AND COURSE: At laparoscopy a 4 cm tumor was palpated in the region of the pancreatic tail. Left resection of the pancreas was performed. Histopathological examination of the surgical specimen confirmed an insulinoma. A repeat of oGTT 6 months postoperatively demonstrated a markedly diminished insulin level compared with the preoperative results, as well as a diabetic metabolic state. CONCLUSION: In case of dramatic improvement of diabetes mellitus in an obese patient without drug treatment or weight reduction an insulin-producing tumour should be considered in the differential diagnosis. There may be no typical hypoglycaemic symptoms because of insulin resistance associated with the obesity.

Combined Modality Therapy↗
PubMed1999

Mutations of the human hepatic lipase gene in patients with combined hypertriglyceridemia/hyperalphalipoproteinemia and in patients with familial combined hyperlipidemia.

Hepatic lipase is an enzyme which hydrolyzes triglycerides from plasma lipoproteins and thus takes part in the metabolism of intermediate density lipoproteins and high-density lipoproteins. The search described here concentrated on mutations of the HL gene in 129 patients with combined hypertriglyceridemia/hyperalphalipoproteinemia and in 184 members of 19 families with familial combined hyperlipidemia. Controls were 100 subjects with favorable lipid values (age 46-51 years). Mutation screening and analysis were performed by temperature-gradient gel electrophoresis, allele-specific restriction genotyping, and sequencing. Six different missense mutations and four different silent mutations were found in the HL gene. The alleles Phe-267 and Gln-343 were detected only once in the patient group with hypertriglyceridemia and hyperalphalipoproteinemia and were not detected in the control group. The allele Met-383 was rare in both patients and controls. We found 9.3% of the patients and only 3.0% of controls to be carrying the Val-73-Met missense mutation. The allele Phe-334 was found in 5.43% of patients and in 2.0% of controls. The difference between the frequencies of these alleles was significant between male patients and male controls (Met-73 P=0.044; Phe-334 P=0.047). Also, the summarized odds ratio of 3.28 (95% confidence interval 1.23-8.73) demonstrates that mutation carriers are significantly more prevalent in the patients. Fifteen carriers of the Met-73 allele were found in six families of the familial combined hyperlipidemia group. Furthermore, six carriers of the Phe-334 allele were found in three families of the same group. In comparison to the controls the summarized odds ratio of 2.45 (95% confidence interval 0.89-6.71) barely missed the level of significance. The linkage between genotype and phenotype was incomplete. These results show an association of the missense mutations Val-73-Met and Leu-334-Phe as susceptibility alleles for combined forms of hyperlipidemia.

Adolescent↗
PubMed1999

Diminished susceptibility to in vitro oxidation of low-density lipoproteins in hypercholesterolemia: key role of alpha-tocopherol content.

Oxidizability of low-density lipoproteins (LDL) in hypercholesterolemia is of clinical relevance, but previous studies revealed diverging results. Therefore, we studied ex vivo oxidation of LDL in plasma samples of 57 hypercholesterolemic and 20 normocholesterolemic volunteers. LDL were isolated by ultracentrifugation and analyzed for lipids and alpha-tocopherol. The formation of conjugated dienes, lipoperoxides and malondialdehyde was measured at 0.1 micromol/l LDL, 3.2 micromol/l CuSO4. We found prolongation of the lagtime (53.6/65.8/71.4 min) with tertiles (< or = 3.17/3.89/14.2 mmol/l) of LDL-cholesterol (LDL-C). Regression analysis revealed that the lagtime increased with the apparent concentrations of cholesterol (P = 0.003) and alpha-tocopherol (P = 0.001) in the oxidation assay. A multiple regression model with the apparent concentrations of alpha-tocopherol, triglycerides and cholesterol explained 40% of the variation in lagtime. The close relationship between plasma concentrations of LDL-C and LDL-alpha-tocopherol (P = 0.002) indicated that LDL contained more of this antioxidant in hypercholesterolemia. This might provide an explanation for the positive relationship between lagtime and LDL-C. The latter was independent of whether LDL-C or LDL-protein was chosen for standardization of the oxidation assay. The formation of conjugated dienes (P = 0.000), lipoperoxides (P = 0.038) and malondialdehyde (P = 0.001) increased with the cholesterol level in the assay. This may be due to the increased load of LDL with cholesterol esters as a substrate for oxidation in hypercholesterolemia. Our data do not support the opinion that hypercholesterolemia is characterized by increased susceptibility of LDL to oxidation.

Adult↗
PubMed1999

Postprandial plasma glucose is an independent risk factor for increased carotid intima-media thickness in non-diabetic individuals.

Postprandial (pp) hyperglycemia--frequently associated with an increase in cardiovascular risk factors--may be damaging for the endothelium. So far, little information exists how glucose, insulin and lipids may affect atherosclerosis in the pp state. Therefore, we evaluated the relationship of pp hyperglycemia, insulin secretion and coronary risk factors to intima-media thickness (IMT) in a non-diabetic risk population. In 403 subjects (147 males, 256 females), aged 40-70 years, in the majority relatives of index cases with type 2 diabetes--a 75 g oral glucose tolerance test was performed together with measurement of insulin fractions, various risk factors and IMT of the common carotid artery. We found a continuous rise of 2h pp insulin fractions along the quintiles of 2h pp plasma glucose. A significant increase of body mass index, waist to hip ratio, triglycerides and decrease of HDL-cholesterol was observed in the top quintile of 2h pp plasma glucose (8.24 > or = pp plasma glucose < 11.1 mmol/l). Albuminuria was significantly enhanced in the 5th quintile. In parallel, IMT was significantly increased in the 5th quintile versus the bottom quintile of 2 h and maximal glucose (range 11.7-15.3 mmol/l) postprandially. After age and sex adjustment pp glucose and C-peptide, total cholesterol, triglycerides and HDL-cholesterol but not fasting plasma glucose were significantly correlated to IMT. In multivariate analysis age, male sex, pp plasma glucose, total and HDL-cholesterol were found to be independent risk factors for increased IMT. In conclusion, our data in a non-diabetic European risk population show that the two top quintiles of pp plasma glucose are associated with a clustering of standard risk factors. Corresponding to this clustering of risk factors IMT was significantly increased in the top quintile of 2 h and maximal pp plasma glucose. These data show that pp hyperglycemia may exert a noxious impact on the arterial wall together with a cluster of anomalies typical for the metabolic syndrome.

Adult↗
PubMed1999

Hypertriglyceridaemia in mild hypertension: impact on cardiovascular and hormonal reactivity under different stress tests.

OBJECTIVES: We investigated the significance of hypertriglyceridaemia (HTG) for associated components of the metabolic syndrome and stress reactivity in subjects with mild hypertension. METHODS: Seventeen asymptomatic subjects with mild hypertension assessed by 24-h blood pressure (BP) measurement plus HTG (TG >2.3 mmol/l) were recruited and compared with age- and sex-matched subjects with hypertension alone and healthy controls. Cardiovascular and hormonal stress reactivity were tested in a standardised programme consisting of 6 min mental stress, 3 min finger grip and a submaximal bicycle ergometry. RESULTS: The hypertensive patients with HTG exhibited significantly higher fasting insulin, uric acid and gamma-GT levels and lower HDL-cholesterol. The cardiovascular reactivity was similar in all three tests with respect to brachial and peripheral BP in the groups. Peripheral BP during the tests was found to be higher particularly in subjects with hypertension alone. The correlations between BP parameters were disturbed in hypertensives with HTG. Latter group showed significantly higher dopamine, noradrenaline, as well as ACTH levels and an increased ACTH/cortisol ratio. CONCLUSION: HTG in mild hypertension is indicative for insulin resistance accompanied by a modified vascular reactivity as well as elevated catecholamines and ACTH.

Adult↗