Measurement of Serum N-Glycans in the Assessment of Early Vascular Aging (Arterial Stiffness) in Adults With Type 1 Diabetes

OBJECTIVE

Vascular aging (arterial stiffness [AS]) is an inflammation-linked process that predicts macro- and microvascular complications in adults with type 1 diabetes (T1D). We evaluated the utility of measuring the inflammation-linked N-glycans GlycA and GlycB to assess vascular aging in adults with T1D.

RESEARCH DESIGN AND METHODS

Eighty-four adults with T1D (>10-year duration without cardiovascular events) and 68 healthy control subjects were evaluated for clinical characteristics (including microvascular complications in patients with T1D), aortic pulse wave velocity (aPWV) (surrogate measure of AS), and serum GlycA and GlycB (peak area [concentration] and height/width [H/W] ratio) using 1H-nuclear magnetic resonance spectroscopy.

RESULTS

Patients with T1D had higher median (interquartile range) values than healthy control subjects for (P < 0.001 for all comparisons) aPWV 7.9 (6.9-9.1) vs. 6.1 (5.5-6.7) m/s, GlycA 850.4 (781.3-916.1) vs. 652.4 (581.5-727.1) μmoL; GlycB 386.1 (353.2-426.3) vs. 310.0 (280.5-331.9) μmol/L), H/W ratio of GlycA 16.5 (14.9-18.1) vs. 15.0 (13.7-16.7), and H/W ratio of GlycB 5.0 (4.6-5.5) vs. 4.0 (3.4-4.3). Moreover, aPWV correlated (P < 0.001 for all correlations) with GlycA (r = 0.550) and GlycB (r = 0.423) concentrations and with H/W ratios of GlycA (r = 0.453) and GlycB (r = 0.510). Adjusting for potential confounders, GlycA concentration (β = 0.212, P < 0.001) and the H/W ratios of GlycA (β = 0.150, P = 0.009) and GlycB (β = 0.155, P = 0.011) remained independently associated with aPWV. C-statistics for detecting individuals with aPWV >10 m/s were 0.866 (95% CI 0.794-0.937) for GlycA levels and 0.862 (0.780-0.943) for H/W ratio of GlycB.

CONCLUSIONS

Measurement of serum GlycA and GlycB may have utility in assessing vascular aging in adults with T1D of >10-year duration and no previous cardiovascular events.

Interpretation of clinical trials on the cardiovascular effects of hypoglycemic drugs in people with type 2 diabetes

Randomized clinical trials on the cardiovascular effects of hypoglycemic drugs on people with type 2 diabetes mellitus began more than fifty years ago. In the last decade, the emergence of new classes of hypoglycemic drugs has led to the development of randomized clinical trials to assess their cardiovascular safety. Known as Cardiovascular Outcome Trials, they have provided a lot of new information that needs to be critically appraised if the knowledge obtained is to be applicable in clinical practice. To this end, the current article first comments on the guidelines to which these trials have adhered, then reviews some concepts for improving their interpretation (such as different types of analyses, the definition of objectives and the evaluation of their results), and concludes by mentioning the new guidelines to which future trials designed to evaluate the safety of new hypoglycemic drugs should adhere.

Arterial Stiffness in Type 1 Diabetes: The Case for the Arterial Wall Itself as a Target Organ

Arterial stiffness (AS) integrates the cumulative burden of known and unknown cardiovascular risk factors on the elastic wall of large arteries along the lifespan of an individual. As a marker of vascular aging, AS is an independent predictor of cardiovascular events and improves cardiovascular risk prediction when added to the Framingham Risk Score. In addition, AS may affect the microvasculature and promote the development of microvascular complications. Its impact on both the macro- and microvasculature has led to the concept that the arterial wall itself should be considered as a target organ. Here, we review the biological and clinical consequences of AS on the macro- and microvasculature and the measurement of AS in routine clinical practice. We also discuss the pathophysiological mechanisms underpinning AS development using diabetes and, in particular, type 1 diabetes, as a disease model with a high risk of cardiovascular events and microvascular complications that are accelerated by AS.

Interpretation of clinical trials on the cardiovascular effects of hypoglycemic drugs in people with type2 diabetes

Randomized clinical trials on the cardiovascular effects of hypoglycemic drugs on people with type2 diabetes mellitus began more than fifty years ago. In the last decade, the emergence of new classes of hypoglycemic drugs has led to the development of randomized clinical trials to assess their cardiovascular safety. Known as Cardiovascular Outcome Trials, they have provided a lot of new information that needs to be critically appraised if the knowledge obtained is to be applicable in clinical practice. To this end, the current article first comments on the guidelines to which these trials have adhered, then reviews some concepts for improving their interpretation (such as different types of analyses, the definition of objectives and the evaluation of their results), and concludes by mentioning the new guidelines to which future trials designed to evaluate the safety of new hypoglycemic drugs should adhere.

Utility of Insulin Resistance in Estimating Cardiovascular Risk in Subjects with Type 1 Diabetes According to the Scores of the Steno Type 1 Risk Engine

BACKGROUND

We sought to assess the potential of insulin resistance (IR) for estimating cardiovascular disease (CVD) risk in adults with type 1 diabetes (T1DM) according to the scores of the Steno Type 1 Risk Engine (ST1RE).

METHODS

A total of 179 adults with T1DM (50.8% men, age 41.2 ± 13.1 years, duration of T1DM 16 (12-23) years) without established CVD were evaluated. IR was assessed by the estimation of insulin sensitivity (eIS) using two validated prediction equations: the estimated insulin sensitivity developed from the Pittsburgh Epidemiology of Diabetes Complications Study (eIS-EDC) and the estimated insulin sensitivity developed from Coronary Artery Calcification in T1DM Study (eIS-CACTI) ST1RE was used to estimate 10-year CVD risk and to classify subjects into three groups according to their risk: low (<10%; n = 105), moderate (10-20%; n = 53), and high (≥20%; n = 21).

RESULTS

Both eIS-EDC and eIS-CACTI correlated negatively with ST1RE scores (eIS-EDC: r = -0.636, p < 0.001; eIS-CACTI: r = -0.291, p < 0.001). The C-statistic for predicting moderate/high risk and high risk was 0.816 (95% confidence interval (CI): 0.754-0.878) and 0.843 (95% CI: 0.772-0.913), respectively, for the eIS-EDC equation, and was 0.686 (95% CI: 0.609-0.763) and 0.646 (95% CI: 0.513-0.778), respectively, for the eIS-CACTI equation. The eIS-EDC equation had a significantly higher C-statistic both for moderate-/high-risk (p = 0.001) and high-risk (p = 0.007) subjects. Two cut-off points of eIS-EDC were identified for detecting moderate/high risk (8.52 mg·kg^-1·min^-1; sensitivity 74% and specificity 76%) and high risk (8.08 mg·kg^-1·min^-1; sensitivity 65% and specificity 95%) with potential applicability in clinical practice.

CONCLUSIONS

eIS negatively correlates with the score of CVD risk in the ST1RE. Two cut-off points of eIS are reported with potential utility in clinical practice for detecting adults with T1DM with the highest CVD risk.

Specific Nuclear Magnetic Resonance Lipoprotein Subclass Profiles and Central Arterial Stiffness in Type 1 Diabetes Mellitus: A Case Control Study

Background: Dyslipidemia has been associated with vascular complications of type 1 diabetes mellitus (T1DM). We examined the proton nuclear magnetic resonance (NMR)-assessed lipoprotein subclass profiles in subjects with T1DM compared with those of healthy subjects and assessed the potential relationship of these profiles with arterial stiffness. Methods: Eighty-four participants with T1DM of at least 10 years duration and no clinical cardiovascular disease (age: 35–65 years; 50% men) and 42 healthy participants were evaluated for: (1) clinical and anthropometric data (including classical cardiovascular risk factors), (2) insulin sensitivity by estimated glucose disposal rate, (3) microvascular complications, (4) NMR-assessed lipoprotein subclass profile, and (5) arterial stiffness (aortic pulse wave velocity). Results: Participants with T1DM had an apparently better conventional lipid profile than healthy participants, but with significant differences in NMR-assessed lipoprotein profiles such as higher triglyceride content of low-density lipoprotein (LDL) and high-density lipoprotein (HDL). In healthy participants, arterial stiffness was associated with NMR-based LDL subclasses. By contrast, in T1DM participants, arterial stiffness was independently associated mainly with NMR-based very-low-density lipoprotein (VLDL) subclasses: positively with total VLDL particles (and subclasses) and VLDL triglyceride content, and negatively with LDL and HDL particle sizes. These results were maintained after adjustments for classical cardiovascular risk factors. Conclusions: Subjects with T1DM, while having an apparently better conventional lipid profile than healthy controls, presented significant alterations in their NMR-assessed lipoprotein profile. The association between arterial stiffness and NMR-assessed lipoprotein profiles also differed in both groups. These results support a potential role of the identified differences in the residual cardiovascular risk in T1DM.

Arterial stiffness is highly correlated with the scores obtained from the Steno Type 1 Risk Engine in subjects with T1DM

Objectives

Currently used risk scores for type 2 diabetes mellitus (T2DM) clearly underestimate cardiovascular risk in type 1 diabetes (T1DM). Hence, there is a need to develop novel and specific risk-estimation tools for this population. We aimed to assess the relationship between the Steno Type 1 Risk Engine (ST1RE) and arterial stiffness (AS), and to identify potential cut-off points of interest in clinical practice.

Design and methods

A total of 179 patients with T1DM (50.8% men, mean age 41.2±13.1 years), without established cardiovascular disease, were evaluated for clinical and anthropometric data (including classical cardiovascular risk factors), and AS measured by aortic pulse-wave velocity (aPWV). The ST1RE was used to estimate 10-year cardiovascular risk and patients were classified into 3 groups: low- (<10%; n = 105), moderate- (10–20%; n = 53) and high-risk (≥20%; n = 21).

Results

When compared with the low- and moderate-risk groups, patients in the high-risk group were older, had higher prevalence of hypertension, dyslipidemia and insulin-resistance, and had higher body-mass index and HbA_1c. aPWV increased in parallel with estimated cardiovascular risk (6.4±1.0, 8.4±1.3 and 10.3±2.6m/s; p<0.001). As an evaluation of model performance, the C-statistic of aPWV was 0.914 (95% confidence interval [CI]:0.873–0.950) for predicting moderate/high-risk and 0.879 (95%CI:0.809–0.948) for high-risk, according to the ST1RE. The best cut-off points of aPWV were 7.3m/s (sensitivity:86%, specificity:83%) and 8.7m/s (sensitivity:76%, specificity:86%) for moderate/high- and high-risk, respectively.

Conclusions

AS is highly correlated with the scores obtained from the ST1RE. We have identified two cut-off points of AS that can clearly discriminate moderate/high- and high-risk T1DM patients, which could be of great value in clinical practice.

FGF-23/Vitamin D Axis in Type 1 Diabetes: The Potential Role of Mineral Metabolism in Arterial Stiffness

Objective

To investigate the usefulness of Fibroblast Growth Factor 23 (FGF-23) and vitamin D as possible biomarkers of pre-clinical atherosclerosis, assessed as arterial stiffness (AS), in a group of subjects with type 1 diabetes (T1DM) and no previous cardiovascular events.

Research Design and Methods

68 T1DM patients and 68 age- and sex-matched controls were evaluated for 1) age, sex, diabetes duration, physical activity, smoking, alcohol intake, BMI, blood pressure, fasting plasma glucose, HbA_1c, estimated glomerular filtration rate (eGFR) and lipid profile; 2) microvascular complications; 3) blood concentrations of FGF-23 and mineral metabolism parameters (calcium, phosphate, parathyroid hormone (PTH) and 25-hydroxy-vitamin D (25(OH)D)); 4) AS, assessed as aortic pulse wave velocity (aPWV); and 5) low-grade inflammation (hsCRP, IL-6, sTNFαR1, sTNFαR2) and endothelial dysfunction (ED) markers (ICAM-1, VCAM-1, E-Selectin).

Results

Patients with T1DM had higher aPWV compared with controls (p<0.001), but they did not present differences in 25(OH)D (70.3(50.4–86.2)nmol/L vs. 70.7(59.7–83.0)nmol/L; p = 0.462) and in FGF-23 plasma concentrations (70.1(38.4–151.9)RU/mL vs. 77.6(51.8–113.9)RU/mL; p = 0.329). In T1DM patients, higher concentrations of FGF-23 were positively associated with aPWV after adjusting for eGFR and classical cardiovascular risk factors (model 1: ß = 0.202, p = 0.026), other mineral metabolism parameters (model 2: ß = 0.214, p = 0.015), microvascular complications, low-grade inflammation and ED markers (model 3: ß = 0.170, p = 0.045). Lower 25(OH)D concentrations were also associated with higher aPWV after adjusting for all the above-mentioned factors (model 3: ß = -0.241, p = 0.015).

Conclusions

We conclude that both FGF-23 plasma concentrations (positively) and 25(OH)D serum concentrations (negatively) are associated with AS in patients with T1DM and no previous cardiovascular events.

Haptoglobin genotype is associated with increased endothelial dysfunction serum markers in type 1 diabetes

BACKGROUND

To evaluate the genotype-driven effect of haptoglobin (Hp) in patients with type 1 diabetes without clinical cardiovascular (CV) disease, considering endothelial dysfunction (ED) and arterial stiffness (AS).

MATERIAL AND METHODS

About 137 patients with type 1 diabetes (duration ≥ 5 years) and 68 age- and sex-matched controls were evaluated for the following: (i) smoking, alcohol intake, BMI, blood pressure, fasting plasma glucose, HbA1c and lipid profile; (ii) microvascular complications; (iii) serum markers of ED (ICAM-1, VCAM-1 and E-selectin); (iv) AS, assessed as aortic pulse wave velocity (aPWV); and (v) Hp genotype.

RESULTS

The prevalence of the 1/1, 2/1 and 2/2 Hp genotypes was 28.5%, 46.7% and 24.8% in patients with type 1 diabetes and 20.9%, 38.8% and 40.3% in controls, respectively. No differences were found in classical CV risk factors between patients homozygous for allele 2 and the remaining genotypes, both in patients with type 1 diabetes and controls. Patients with type 1 diabetes carrying the Hp2/2 genotype had higher concentrations of ICAM-1 (65.1 (56.7-76.0) ng/mL vs. 59.0 (51.7-69.3) ng/mL; P = 0.033) and sVCAM-1 (1133.1 (884.6-1458.6) ng/mL vs. 956.4 (738.5-1206.1) ng/mL; P = 0.040) than those without it. The Hp2/2 genotype remained independently associated with ED after adjusting for CV risk factors (P = 0.038). No significant differences were found for aPWV between Hp genotypes.

CONCLUSIONS

Endothelial dysfunction may be influenced by Hp2/2 genotype in patients with type 1 diabetes with independence of classical CV risk factors.

Advanced glycation end products are associated with arterial stiffness in type 1 diabetes

The aim of this study was to investigate the relationship between advanced glycation end products (AGEs) and arterial stiffness (AS) in subjects with type 1 diabetes without clinical cardiovascular events. A set of 68 patients with type 1 diabetes and 68 age- and sex-matched healthy subjects were evaluated. AGEs were assessed using serum concentrations of N-carboxy-methyl-lysine (CML) and using skin autofluorescence. AS was assessed by aortic pulse wave velocity (aPWV), using applanation tonometry. Patients with type 1 diabetes had higher serum concentrations of CML (1.18 vs 0.96 μg/ml; P=0.008) and higher levels of skin autofluorescence (2.10 vs 1.70; P<0.001) compared with controls. These differences remained significant after adjustment for classical cardiovascular risk factors. Skin autofluorescence was positively associated with aPWV in type 1 diabetes (r=0.370; P=0.003). No association was found between CML and aPWV. Skin autofluorescence was independently and significantly associated with aPWV in subjects with type 1 diabetes (β=0.380; P<0.001) after adjustment for classical cardiovascular risk factors. Additional adjustments for HbA1c, disease duration, and low-grade inflammation did not change these results. In conclusion, skin accumulation of autofluorescent AGEs is associated with AS in subjects with type 1 diabetes and no previous cardiovascular events. These findings indicate that determination of tissue AGE accumulation may be a useful marker for AS in type 1 diabetes.

Impaired endothelial function is not associated with arterial stiffness in adults with type 1 diabetes

AIM

This study investigated the relationship between endothelial dysfunction (ED) and arterial stiffness (AS) in adults with type 1 diabetes and no clinical cardiovascular (CV) disease.

METHODS

A total of 68 patients with type 1 diabetes and 68 age- and gender-matched healthy (non-diabetic) subjects were evaluated. ED was assessed by reactive hyperaemia peripheral arterial tonometry (RH-PAT) and by serum concentrations of soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1) and E-selectin. AS was assessed by aortic pulse wave velocity (aPWV). All statistical analyses were stratified by gender.

RESULTS

Adults with type 1 diabetes had RH-PAT index scores similar to those of their matching controls [men: 1.55 (1.38-1.98)% versus 1.61 (1.40-2.17)%, P=0.556; women: 2.07 (1.55-2.31)% versus 2.08 (1.79-2.49)%; P=0.215]. However, after adjusting for potential confounders, type 1 diabetes emerged as the main determinant of the RH-PAT index in women. Also, differences between genders in both the controls and type 1 diabetes patients disappeared. Men with diabetes had higher serum concentrations of E-selectin, and women had higher serum concentrations of sICAM-1, sVCAM-1 and E-selectin than their respective controls. However, after adjusting for potential confounders, only the differences in sICAM-1 (women) and E-selectin (both genders) remained significant. No association was found between aPWV and the RH-PAT index and ED markers after adjusting for CV risk factors.

CONCLUSION

ED was increased in adults with type 1 diabetes compared with age-matched non-diabetic subjects. Also, gender differences in ED were lost in type 1 diabetes. However, ED was not associated with AS after adjusting for potential confounders. These findings suggest that ED occurs earlier than AS in type 1 diabetes.

Can augmentation index substitute aortic pulse wave velocity in the assessment of central arterial stiffness in type 1 diabetes?

The aim of this study was to test whether the augmentation index adjusted for heart rate (AIx@HR75) can be used as a substitute for aortic pulse wave velocity (aPWV) in the measurement of arterial stiffness (AS) in type 1 diabetes. Sixty-eight patients with type 1 diabetes and 68 age- and sex-matched controls were evaluated. AS was assessed by aPWV and AIx@HR75 using applanation tonometry. Subjects with type 1 diabetes had higher aPWV compared to controls, but no differences were found between groups regarding AIx@HR75 [men: 10.75 % (2.63-20.75) vs. 8.25 % (4.00-11.38); p = 0.462. Women: 20.75 % (5.00-30.16) vs. 14.50 % (11.38-22.16); p = 0.418]. In univariate analyses, aPWV correlated positively with AIx@HR75 in both groups (type 1: r = 0.340, p = 0.005; healthy subjects: r = 0.451, p < 0.001). However, AIx@HR75 was not associated with aPWV after adjustment for cardiovascular risk factors in multivariate models (type 1: p = 0.342; healthy subjects: p = 0.976). Our findings suggest that AIx@HR75 should not be used as a substitute for aPWV for measuring AS in type 1 diabetes.

Serum levels of TWEAK and scavenger receptor CD163 in type 1 diabetes mellitus: relationship with cardiovascular risk factors. a case-control study

OBJECTIVE

To test the usefulness of serum concentrations of tumor necrosis factor-like weak inducer of apoptosis (sTWEAK) and soluble scavenger receptor CD163 (sCD163) as markers of subtle inflammation in patients with type 1 diabetes mellitus (T1DM) without clinical cardiovascular (CV) disease and to evaluate their relationship with arterial stiffness (AS).

METHODS

Sixty-eight patients with T1DM and 68 age and sex-matched, healthy subjects were evaluated. Anthropometrical variables and CV risk factors were recorded. Serum concentrations of sTWEAK and sCD163 were measured. AS was assessed by aortic pulse wave velocity (aPWV). All statistical analyses were stratified by gender.

RESULTS

T1DM patients showed lower serum concentrations of sTWEAK (Men: 1636.5 (1146.3-3754.8) pg/mL vs. 765.9 (650.4-1097.1) pg/mL; p<0.001. Women: 1401.0 (788.0-2422.2) pg/mL vs. 830.1 (562.6-1175.9) pg/mL; p = 0.011) compared with their respective controls. Additionally, T1DM men had higher serum concentrations of sCD163 (285.0 (247.7-357.1) ng/mL vs. 224.8 (193.3-296.5) ng/mL; p = 0.012) compared with their respective controls. sTWEAK correlated negatively with aPWV in men (r = -0.443; p<0.001). However, this association disappeared after adjusting for potential confounders. In men, the best multiple linear regression model showed that the independent predictors of sTWEAK were T1DM and WHR (R(2) = 0.640; p<0.001). In women, T1DM and SBP were the independent predictors for sTWEAK (R(2) = 0.231; p = 0.001).

CONCLUSION

sTWEAK is decreased in T1DM patients compared with age and sex-matched healthy subjects after adjusting for classic CV risk factors, although sTWEAK levels may be partially influenced by some of them. Additionally, T1DM men have higher serum concentrations of sCD163. These results point out an association between the inflammatory system and CV risk in T1DM.

Fasting plasma peptide YY concentrations are increased in patients with major depression who associate weight loss

BACKGROUND

Many patients with major depression refer a decreased appetite and weight loss among their symptoms. Peptide YY (PYY) and ghrelin belong to the family of peptides of the gut-brain axis implicated in the regulation of appetite and energy metabolism. PYY stimulates a powerful central satiety response and ghrelin increases food intake and weight gain. Brain-derived neurotrophic factor (BDNF) also contributes to the central control of food intake as an anorexigenic factor.

AIM

To study fasting plasma total and acylated ghrelin, plasma PYY and serum BDNF levels in patients with major depression with weight loss as one of their symptoms and compare them with matched healthy controls.

SUBJECTS AND METHODS

Fifteen adult patients, 9 male and 6 female, with recent diagnosis of major depression, and 16 healthy adult subjects, matched by age and anthropometric parameters were studied. All depressed patients referred weight loss and were not under antidepressant therapy. Fasting total PYY, total ghrelin and acylated ghrelin and BDNF were determined.

RESULTS

Fasting total PYY was higher in patients than controls (2.01±0.09 vs 1.29±0.16 pmol/l). There were no differences in fasting total ghrelin, acylated ghrelin or BDNF levels.

CONCLUSIONS

Major depressed patients, with weight loss at diagnosis, showed higher fasting plasma PYY levels that could contribute to their reduced appetite.

Insulin resistance, low-grade inflammation and type 1 diabetes mellitus

To assess the relationships between insulin resistance and low-grade inflammation in subjects with type 1 diabetes mellitus (T1DM) who do not have clinical macrovascular complications. A total of 120 subjects diagnosed with T1DM 14 years before were evaluated for the following: (1) sex, age, body mass index, waist-to-hip ratio (WHR), blood pressure, smoking, alcohol intake, insulin dose, HbA1c and lipid profile; (2) microvascular complications; (3) plasma concentrations of soluble fractions of tumour necrosis factor-α receptors type 1 and 2, interleukin-6, adiponectin, leptin and high-sensitivity C-reactive protein (hs-CRP); and (4) insulin resistance (estimation of the glucose disposal rate-eGDR). Those subjects with an eGDR below the median of the same sex group were classified as insulin resistant and the others as insulin sensitive. Insulin-resistant men, compared to the insulin-sensitive, had higher WHR (0.89 ± 0.08 vs. 0.83 ± 0.05; P < 0.01), higher systolic [121 (118-125) vs. 114 (108-120) mmHg; P = 0.01] and diastolic [73 (66-80) vs. 67 (70-73) mmHg; P = 0.02] blood pressures, higher HbA1c values [8.7 (8.1-9.9) vs. 7.5 (7.2-8.0) %; P < 0.01] and higher hs-CRP concentrations [1.16 (0.61-3.20) vs. 0.49 (0.31-0.82) mg/dl; P = 0.01], but no other significant differences between groups were found. Insulin-resistant women had higher WHR and HbA1c values, compared to the insulin-sensitive, but they did not have any other differences. In men, hs-CRP correlated significantly with WHR and HbA1c (r = 0.363; P = 0.016 and r = 0.317; P = 0.036, respectively), after adjusting for age, alcohol intake, smoking and microvascular complications. Insulin-resistant men with T1DM have an increase in plasma concentrations of hs-CRP. Central obesity and HbA1c are its main determinants.

Plasma visfatin concentrations increase in both hyper and hypothyroid subjects after normalization of thyroid function and are not related to insulin resistance, anthropometric or inflammatory parameters

OBJECTIVE

The objective of this study was to evaluate plasma visfatin levels in thyroid dysfunction and its relationship with inflammatory, anthropometric and insulin resistance parameters.

DESIGN AND PATIENTS

Twenty-four hyperthyroid and 27 hypothyroid patients were studied before and after treatment. Forty-five euthyroid subjects were used as control group.

MEASUREMENTS

Fasting plasma visfatin, IL-6, C reactive protein, adiponectin, thyroid hormones, waist-to-hip ratio, BMI, percentage of body fat and homeostasis model insulin resistance index (HOMA-IR) were measured.

RESULTS

Hyperthyroid patients showed increased insulin resistance, IL-6 and visfatin levels compared with controls (3.21 +/- 3.0 vs. 1.67 +/- 0.75, P = 0.022; 3.35 +/- 0.41 vs. 2.10 +/- 0.25 pg/ml, P = 0.016; and 37.4 +/- 5.81 vs. 23.79 +/- 4.2 ng/ml, P = 0.061 respectively). After normalization of thyroid function, IL-6 levels and HOMA-IR decreased (2.35 +/- 0.37 vs. 2.10 +/- 0.25 pg/ml, P = 0.045 and 3.21 +/- 0.60 vs. 2.28 +/- 0.38, P = 0.032 respectively), while body weight, adiposity and visfatin levels increased (26.1 +/- 1.2 vs. 26.7 +/- 1.2 kg/m(2), P = 0.049; 30.9 +/- 1.6 vs. 32.2 +/- 1.6%, P = 0.007; and 37.4 +/- 5.81 vs. 63.13 +/- 8.72 ng/ml, P = 0.047 respectively). C reactive protein and adiponectin levels were similar to those of the control group. Hypothyroid patients showed high visfatin levels (40.59 +/- 3.07 vs. 29.34 +/- 4.9 ng/ml, P = 0.049) that increased after treatment (81.4 +/- 9.2 ng/ml, P = 0.001) without changes in anthropometric or insulin resistance parameters. C reactive protein, IL-6 and adiponectin levels were similar to those of the control group. No correlations between visfatin and any analysed parameter were found in either hyper- or hypothyroidism.

CONCLUSION

Visfatin exhibits a marked increase after normalization of thyroid function in both hyper and hypothyroid patients. We suggest that visfatin may play a role in the hormone stabilization process independent of anthropometric, inflammatory or insulin resistance variables.

Role of vitamin D in the pathogenesis of type 2 diabetes mellitus

Vitamin D deficiency has been shown to alter insulin synthesis and secretion in both humans and animal models. It has been reported that vitamin D deficiency may predispose to glucose intolerance, altered insulin secretion and type 2 diabetes mellitus. Vitamin D replenishment improves glycaemia and insulin secretion in patients with type 2 diabetes with established hypovitaminosis D, thereby suggesting a role for vitamin D in the pathogenesis of type 2 diabetes mellitus. The presence of vitamin D receptors (VDR) and vitamin D-binding proteins (DBP) in pancreatic tissue and the relationship between certain allelic variations in the VDR and DBP genes with glucose tolerance and insulin secretion have further supported this hypothesis. The mechanism of action of vitamin D in type 2 diabetes is thought to be mediated not only through regulation of plasma calcium levels, which regulate insulin synthesis and secretion, but also through a direct action on pancreatic beta-cell function. Therefore, owing to its increasing relevance, this review focuses on the role of vitamin D in the pathogenesis of type 2 diabetes mellitus.

Adult subjects with Prader-Willi syndrome show more low-grade systemic inflammation than matched obese subjects

AIM

Adult subjects with Prader-Willi syndrome (PWS) may show several conditions that are associated with an activation of innate immunity such as obesity, deficient GH secretion or hypogonadism. Our aim was to study whether obese adult PWS subjects show an additional low-grade systemic inflammation (LGSI) in relation to obese adult non-PWS subjects and lean healthy control subjects before and after a standardized liquid meal.

METHODS

Seven obese adult PWS subjects, 7 matched obese non-PWS subjects and 7 lean healthy control subjects were studied for 6 h from the administration of a standard liquid meal.

RESULTS

Compared to non-PWS, PWS subjects showed higher plasma concentrations of C-reactive protein (CRP) (p=0.030), complement component C3 (p=0.018), interleukin(IL)-18 (p=0.048), and IL-6 (p=0.041) that persisted post-prandially elevated for CRP (p<0.0001), C3 (p=0.015), and IL-18 (p=0.003). Tumor necrosis factor(TNF)-alpha did not differ between the 3 groups. These results were independent from IGF-I levels, homeostasis model assessment index, and body mass index (BMI). In male subjects with PWS, testosterone levels correlated to IL-18 (r=-0,646, p=0.041).

CONCLUSIONS

Compared to matched non-PWS subjects, the obese PWS subjects in this study showed an additional LGSI that persisted postprandially and was independent from BMI, insulin resistance, and deficient GH secretion. However, in PWS males, high IL-18 levels were related to low testosterone concentrations.

A lesser postprandial suppression of plasma ghrelin in Prader-Willi syndrome is associated with low fasting and a blunted postprandial PYY response

OBJECTIVE

Ghrelin and polipeptide YY (PYY) are involved in the regulation of food intake. We evaluated these two peptides and their possible relationship in adult patients with Prader-Willi syndrome (PWS).

PATIENTS

Seven patients with PWS, 16 age-sex-BMI matched obese and 42 age-sex matched lean subjects.

DESIGN AND MEASUREMENTS

Fasting plasma PYY and ghrelin levels were measured in all subjects and, postprandially until 6 h, in seven matched subjects of each group.

RESULTS

Fasting ghrelin levels were higher in PWS than in the other two groups. Fasting PYY levels were lower in patients with PWS than in lean subjects but similar to those in obese subjects. The postprandial decrease in ghrelin concentrations was lower in PWS as compared to the other two groups and therefore the 6-h-postprandial area under the curve (AUC) for ghrelin was higher in PWS than in obese subjects. PYY response after the meal was blunted in patients with PWS, but not in the other two groups that showed a peak at 60 min The AUC for PYY was lower in PWS as compared to the other two groups. Fasting PYY levels correlated negatively with fasting ghrelin levels and with ghrelin AUC and they were the only predictor for ghrelin AUC (beta = -0.464, P = 0.034). The increase in PYY correlated negatively with the decrease in ghrelin at times 60 min and 120 min in PWS.

CONCLUSIONS

In PWS, the low decrease in postprandial ghrelin levels could be related to the low fasting PYY concentrations and their blunted postprandial response.

Increased cholesterol intake in women with gestational diabetes mellitus

AIM

Cholesterol intake is associated with the risk for type 2 diabetes mellitus, but no previous studies have evaluated its role regarding the risk of gestational diabetes mellitus (GDM). We investigate the relation between cholesterol intake and GDM.

METHODS

At screening for GDM, 335 pregnant women were evaluated for dietary intake (including cholesterol) during the previous year (validated food-frequency questionnaire).

RESULTS

Forty-one women were diagnosed with GDM and 294 did not meet the GDM criteria. Women with GDM were older (32.8+/-0.7 vs. 30.2+/-0.3 years; P=0.01) and had a higher body mass index (27.3+/-0.7 vs. 24.3+/-0.3 kg/m2; P=0.01) than women without GDM. They also had more frequently a family history of type 2 diabetes mellitus (51.2% vs. 40.0%; P=0.02) and history of previous GDM (14.6% vs. 1.7%; P=0.01), and were evaluated earlier in pregnancy (22.1+/-1.2 vs. 24.9+/-0.5 weeks; P=0.03). There were no significant differences between groups in smoking habit, and alcohol, total energy, protein, carbohydrate, fats and fiber intake. Women with GDM had a higher cholesterol intake than women without GDM (145.3+/-4.5 mg/1000 kcal vs. 134.5+/-1.6 mg/1000 kcal; P=0.03). In a multiple logistic regression model, previous GDM, BMI, age and cholesterol intake (OR=1.88; 95% CI: 1.09-3.23 for each increase of 50 mg/1000 kcal) were independently and positively associated with GDM.

CONCLUSION

We conclude that cholesterol intake is independently associated with GDM and that it could be involved in the pathogenesis of GDM.

The tumour necrosis factor (TNF)-alpha system is activated in accordance with pulse pressure in normotensive subjects with type 1 diabetes mellitus

OBJECTIVE

Pulse pressure (PP) and inflammation are important predictors of cardiovascular disease (CVD), even in the normotensive. The age-related increase in PP can be diagnosed up to 20 years earlier in subjects with type 1 diabetes mellitus (T1DM) than in the general population. Some evidence suggests that PP can stimulate inflammation. Our aim was to study the relationship between PP and plasma inflammatory proteins in normotensive subjects with T1DM.

DESIGN

This was a cross-sectional study of a group of normotensive (<140/80 mmHg) subjects diagnosed with T1DM 14 years before. None of them had clinically proven CVD or inflammatory conditions or were on antiplatelet, antihypertensive, anti-inflammatory or lipid-lowering treatment.

METHODS

The following information was recorded: sex, age, body-mass index (BMI), waist-to-hip ratio (WHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), PP, mean blood pressure (MBP), smoking, alcohol intake, insulin dose, lipid profile, HbA1c, microvascular complications, and plasma concentrations of soluble receptor types 1 and 2 of tumour necrosis factor (TNF)-alpha (sTNFR1 and sTNFR2, respectively), interleukin-6, C-reactive protein, adiponectin and leptin.

RESULTS

A total of 112 subjects were evaluated (aged 27.4+/-6.6 years, 52.7% women, BMI: 20.4+/-2.7 kg/m2, WHR: 0.82+/-0.09, SBP: 112+/-12 mmHg, DBP: 68+/-9 mmHg, PP: 45+/-9 mmHg, MBP: 82+/-9 mmHg, HbA1c: 8.2% (7.3-9.0%), 41.1% microvascular complications). After adjusting for potential confounders, only inflammatory markers of the TNF-alpha system correlated significantly with PP (Pearson correlation coefficient between sTNFR1 and PP: r = 0.215, P = 0.030; and between PP and sTNFR2: r = 0.238, P = 0.020).

CONCLUSION

In normotensive subjects with T1DM after 14 years of diagnosis, the activation of the TNF-alpha system is positively associated with PP levels. This finding might suggest a pathogenic role of the TNF-alpha system in the development of cardiovascular disease in T1DM.

Diabetic neuropathy is associated with activation of the TNF-alpha system in subjects with type 1 diabetes mellitus

OBJECTIVE

The development of diabetic neuropathy (DN) is predicted by cardiovascular risk factors associated with insulin resistance. As inflammation seems to be implicated in the pathogenesis of insulin resistance, we investigated whether subjects with type 1 diabetes mellitus (T1DM) and DN have an increase in plasma concentrations of inflammatory proteins involved in insulin resistance.

DESIGN

Cross-sectional. Patients One hundred twenty subjects, all diagnosed with T1DM 14 years before.

MEASUREMENTS

(1) Sex, age, body mass index, waist-to-hip ratio (WHR), blood pressure, smoking, alcohol intake, insulin dose, HbA1c and lipid profile; (2) DN (peripheral and cardiac autonomic), retinopathy and nephropathy; (3) plasma concentrations of soluble fractions of tumour necrosis factor alpha receptors 1 and 2 (sTNFR1 and sTNFR2), interleukin-6, high-sensitive C-reactive protein, adiponectin and leptin; and (4) insulin resistance (by way of a mathematical estimation of the glucose disposal rate - eGDR-).

RESULTS

Thirty-six subjects had DN and 84 did not. Subjects with DN received higher insulin doses (57.6 +/- 16.7 vs. 49.2 +/- 15.0 IU/day; P = 0.008) and had higher WHR (0.85 +/- 0.07 vs. 0.81 +/- 0.10; P = 0.007) and HbA1c values (8.5 (7.6-9.6) vs. 7.7 (7.3-8.9)%; P = 0.049) than subjects without DN. They also had higher values of sTNFR1 (2.42 +/- 0.60 vs. 1.96 +/- 0.66 microg/l; P = 0.001) and sTNFR2 (4.73 +/- 1.33 vs. 4.14 +/- 1.09 microg/l; P = 0.015), and were more insulin resistant (eGDR values: 7.28 (5.83-8.03) vs. 8.30 (7.17-9.03) mg kg(-1) min(-1); P = 0.003). The relationship between DN and either sTNFR1 or sTNFR2 remained essentially unchanged after adjusting for several confounders, including glycaemic control, WHR, lipid profile, blood pressure and other microvascular complications (OR for sTNFR1: 2.592 (1.222-5.498), P = 0.013; OR for sTNFR2: 2.124 (1.258-3.587), P = 0.005).

CONCLUSIONS

The activity of the TNF-alpha system is increased in subjects with type 1 diabetes mellitus and diabetic neuropathy, regardless of their glycaemic control and cardiovascular risk factors associated with insulin resistance. These results suggest that TNF-alpha may play a pathogenic role in the development of diabetic neuropathy.

Circulating ghrelin in thyroid dysfunction is related to insulin resistance and not to hunger, food intake or anthropometric changes

OBJECTIVE

Ghrelin is a gastric peptide that plays a role in appetite stimulation, energy balance and possibly in insulin resistance. Hyperthyroidism is a situation where negative energy balance and insulin resistance coexist, while in hypothyroidism a positive energy balance and normal insulin sensitivity predominate. We investigated ghrelin levels and their relationship with hunger, food intake and both anthropometric and insulin resistance parameters in patients with thyroid dysfunction.

DESIGN AND METHODS

We studied 24 hyperthyroid and 17 hypothyroid patients before and after normalisation of thyroid hormone levels and their respective body mass index (BMI)-matched control group. We measured plasma ghrelin levels, homeostasis model assessment of insulin resistance (HOMA-IR) index, a hunger score, mean three-day calorie intake and anthropometric parameters.

RESULTS

In hyperthyroidism, HOMA-IR index was higher (3.21 +/- 0.60 vs 1.67 +/- 0.15 mMmU/l; P = 0.014, t test for independent data) and ghrelin levels were lower (463.6 +/- 36.4 vs 561.1 +/- 32.1 pg/ml; P = 0.041, Mann-Whitney U-test) than in its control group and both normalised after treatment (HOMA-IR: 2.28 +/- 0.38 mMmU/l; P = 0.106, t test for independent data, and ghrelin: 539.7 +/- 45.4 pg/ml; P = 0.549, Mann-Whitney U-test). Glucose, as a component of HOMA-IR index was the only predictor for ghrelin levels (beta = -0.415, P = 0.044, stepwise multiple regression analysis). In hypothyroidism, HOMA-IR index and ghrelin levels were similar to those in its control group both before and after treatment. In both thyroid dysfunction states, no correlations were observed between changes in ghrelin levels and in free T4, free T3, anthropometric parameters, total calorie intake and hunger score.

CONCLUSIONS

In thyroid dysfunction states, ghrelin levels seemed to be in relation to insulin resistance and not to energy balance and food intake regulation, as seen in other physiological and pathological states.

Dissemination of 'patient-oriented evidence that matters' on the Internet: the case of Type 2 diabetes treatment

AIMS

To evaluate the dissemination of patient-oriented evidence that matters (POEMs) derived from the UK Prospective Diabetes Study (UKPDS) through health information websites.

METHODS

Google and Altavista search engines were used to generate a list of websites about Type 2 diabetes treatments. We evaluated a random sample of 50 websites from each list, plus the first 10 websites displayed on each search engine looking for the presence of POEMs about diabetes treatment derived from the UKPDS. Websites were also ranked using the DISCERN instrument.

RESULTS

The final sample consisted of 66 websites. The most frequently stated item was that tight blood pressure decreased complications and/or mortality (55.5%). The effects of metformin on morbidity and/or mortality in overweight patients and the greater effect of control of blood pressure rather than blood glucose control on complications were stated in 18.2 and 16.7% of cases, whereas the lack of effect of tight blood glucose control on premature mortality and of insulin or sulphonylureas on aggregate micro- or macrovascular outcomes in overweight patients were stated in one case each (1.5%). The lack of effect of tight blood glucose control on quality of life was not stated in any website. POEMs were more frequently present in websites rated high with the DISCERN instrument, websites with the Health-on-the-Net seal and non-commercial websites.

CONCLUSIONS

The dissemination of POEMs through the Internet is poor. If patients are to be involved in decision-making processes, efforts should be made to update the Internet contents to meet this challenge.

Translation of the recommendations for the diagnosis of diabetes mellitus into daily clinical practice in a primary health care setting

AIMS

to assess the implementation of 1985 recommendations for the diagnosis of diabetes (World Health Organization [WHO]) in a primary care setting, and the physician's attitude toward the diagnosis of diabetes mellitus (DM).

MATERIAL AND METHODS

Subjects with a fasting plasma glucose (FPG)>6.1 mmol/l (> or =110 mg/dl) and with previously unknown glucose tolerance status were identified retrospectively in a primary health care center during a 45-month period. The following variables were evaluated: anthropometric parameters, fasting plasma glucose and oral glucose tolerance test (OGTT) values, registration of a diagnosis of diabetes in clinical records, smoking status, lipid profile and blood pressure.

RESULTS

1181 subjects with a FPG>6.1 mmol/l were identified (target population): 171 with a FPG>7.8 mmol/l and 1010 with a FPG between 6.1 and 7.7 mmol/l. In the latter group, an OGTT was performed in 553 subjects (54.8%) (173 yielded a diagnosis of diabetes). During the study period, diabetes was diagnosed in 29.1% (n=344) of the target population. Following the 1985 WHO recommendations, a confirmatory diagnostic test was repeated in 92 (69.7%) subjects with a FPG between 7.8 and 11.0 mmol/l, and in 132 subjects (23.87%) who had already received an initial OGTT. The analysis of the diagnostic process followed by the different physicians revealed a high interindividual variability in terms of: proportion of cases diagnosed as diabetes by an OGTT (from 35.7 to 65.2), percentage of subjects with a FPG 6.1-7.7 mmol/l without an OGTT (7.33-70.27%), proportion of confirmatory OGTTs (0-57.89%), and percentage of misdiagnosed cases (1.16-6.34%). The percentage of subjects misdiagnosed was negatively correlated with the proportion of OGTT repetitions.

CONCLUSIONS

1985 WHO recommendations for the diagnosis of diabetes are only partially followed at a primary health care level. There is a high interindividual variability among physicians in the implementation of these recommendations that is associated with the misdiagnosis of diabetes.

Evaluación del proceso y los resultados de la atención a los pacientes diabéticos en un hospital

For the purpose of establishing a specific information system in order to identify the diabetic patients looked after in the hospital and evaluate the processes and the clinical outcomes obtained, a prospective descriptive study was designed--in the Corporació Parc Taulí of Sabadell (Barcelona)--about the diabetic patients cared starting in January 1998, through a clinical registry and other hospital sources of information. Seven hundred and fifty-five patients were identified, and the completeness of the registry was 98%. It was feasible the integration of the registry of admissions with that of the laboratory, that of the discharges from hospital, that of pharmacy and the specific clinical registry. An evaluation of the glycemic control was made in around 90% of the patients, and the registry of the organic explorations was higher than 87%. Although it was not possible in this study, the incorporation of the information from the primary care would complete the follow-up of the patients.

Evaluation of accessibility and use of new communication technologies in patients with type 1 diabetes mellitus

BACKGROUND

The role of patients in the management and control of type 1 diabetes mellitus, a chronic disease, is well established. The advent of new communication technologies is expected to improve patients' access to health information. However, little is known about the extent to which patients with type 1 diabetes mellitus use the Internet to retrieve medical information and about the impact, if any, this retrieval has on their health status.

OBJECTIVE

To evaluate the accessibility and use of new communication technologies in a population of patients with type 1 diabetes mellitus.

METHODS

Patients with type 1 diabetes mellitus attending the Diabetes Clinic of the Hospital de Sabadell, Sabadell, Spain, in a 6-month period were asked to answer a structured questionnaire about education level, Internet accessibility, use of health-related Web sites, and mobile-phone ownership and use.

RESULTS

Of 302 patients with type 1 diabetes mellitus attending the Diabetes Clinic on a regular basis, 244 (115 men, 129 women) were interviewed (response rate 80.8%). Personal computers were owned by 58.2% of patients. Fifty-nine percent had access to the Internet, 39.3% had access to the Internet at home; however, only 36.5% were regular Internet users. Internet users were younger, more frequently men, and of higher education level. Among Internet users only 49.4% had ever accessed a health-related Web site. Internet users who had ever accessed a health-related Web site had a higher level of education, presented severe hypoglycemia more frequently, and were more likely to have access to the Internet at home. No differences were found in metabolic control between Internet users and nonusers or between Internet users who had ever accessed a health-related Web site and Internet users who had never accessed a health-related Web site. Of the 76.6% of the patients that owned a mobile phone, 96% used it more than once a week.

CONCLUSIONS

The impact of new communication technologies might be jeopardized by the low rate of access and utilization of the Internet for health-related purposes. Because of their high rate of ownership and use, mobile phones show promise as a tool in health care communication technologies.

[Hypovitaminosis D: its high prevalence in elderly outpatients in Barcelona. Associated factors]

BACKGROUND

Hypovitaminosis D is a frequent finding in the elderly of northern countries. In Spain because of high sun irradiation it has been traditionally considered that hypovitaminosis D is not a frequent problem. In this study we have evaluated the prevalence of hypovitaminosis D in the elderly and the associated factors.

SUBJECTS AND METHODS

All individuals older than 65 years attending a primary care unit (november 1995-march 1996) and without any disease modifying vitamin D status were included. The following data were recorded: age, gender, height, weight, white and red cell counts, glycaemia, serum ions, albuminemia, plasma creatinine, creatinine clearance, urinary creatinine and calcium, parathyroid hormone (PTHi), calcidiol and calcitriol. Sun exposure and fish ingestion was also determined by questionnaire.

RESULTS

127 individuals were evaluated (age: mean [SD] 74.8 [6.4] years; 47 men, 37.0%). Forty-four subjects (34.6%; CI 95%: 26.3-42.9%) had calcidiol levels < or = 10 ng/ml, 15 (11.8%; CI 95%: 6.2-17.4%) low values of calcidiol, and 13 (10.2%; CI 95%: 4.9-15.5%) high PTHi values. Subjects with hypovitaminosis D (calcidiol levels < or = 10 ng/ml) were mainly women, older, short stature, had a lower values of body surface, albuminemia, phosphatemia, creatinine clearance, sun exposure and fish intake and higher PTHi levels. In the logistic regression model, hypovitaminosis D was positively associated with age and negatively with sun exposure, albuminemia, height and phosphoremia.

CONCLUSIONS

Hypovitaminosis D is a very frequent finding in Spanish elderly people. Its presence is independently associated with age (positively) and sun exposure, serum albumin, height and phosphoremia (negatively).

Cryopreservation: in vitro results in rat pancreatic islets

Cryopreservation is an effective method of islet storage and may facilitate clinical trials of islet transplantation. It was the aim of the present study to evaluate the in vitro viability of cryopreserved rat islets, including the response to nonglucose secretagogues and glucose oxidation. After pancreatic digestion via intraductal injection of collagenase, 75- to 200-micron Wistar rat islets were handpicked and cultured in RPMI 1640 (glucose 11.1 mmol/L) and randomized into two groups: control (cultured 20 to 24 hours at 37 degrees C) and cryopreserved (after 20 to 24 hours of culture at 37 degrees C, islets were cryopreserved according to Rajotte's protocol: freezing velocity, -0.25 degree C/min; thawing velocity, 200 degrees C/min). In the two groups, we evaluated recovery, insulin content per islet, staining viability (ethidium bromide/orange acridine; semiquantitative scoring, measuring the viable area of the islet from 0 = less viable to 3 = more viable), insulin secretion after glucose and nonglucose secretagogues, and oxidation of D-[U-14C]glucose. The results for the control group were always higher for the following: recovery (95.4% +/- 1.2% v 83.0% +/- 2.1%, P = .00), insulin content (2,203.9 +/- 335.2 v 1,443.3 +/- 171.8 microU/islet, P = .03), insulin secretion after 5.5 mmol/L glucose (61.3 +/- 8.0 v 28.3 +/- 3.4 microU/islet/90 min, p = .00), 16.7 mmol/L glucose (151.4 +/- 16.1 v 98.7 +/- 14.1 microU/islet/90 min, p = .03), 10 mmol/L L-leucine +10 mmol/L L-glutamine (125.6 +/- 27.9 v 56.8 +/- 6.4 microU/islet/90 min, P = .05), and 10 mmol/L L-arginine (202.5 +/- 27.5 v 128.8 +/- 14.2 microU/islet/90 min, P = .01), and glucose oxidation at 5.5 mmol/L (12.5 +/- 1.1 v 7.9 +/- 0.6 pmol/islet/120 min, P = .00) and at 16.7 mmol/L (26.1 +/- 2.6 v 14.3 +/- 1.6 pmol/islet/120 min, P = .00). No significant differences in staining viability were found between groups (2.35 and 2.48, respectively, P = .55). However, cryopreserved and control islets showed a significant increase in insulin secretion and glucose oxidation after increasing the glucose concentration from 5.5 to 16.7 mmol/L. We conclude that when glucose is increased, cryopreserved islets keep the capacity to increase insulin secretion, but cryopreservation produces a significant decrease in several islet viability characteristics. This decrease may be due to a decline of beta-cell number per islet and/or a decrease in the content of insulin per beta cell.

[Non-insulin dependent diabetes mellitus: care in an area of Barcelona]

BACKGROUND

Most non-insulin dependent diabetes mellitus (NIDDM) care is provided at the primary care level. The aim of this study was to evaluate the recommendations of the European NIDDM Policy Group (ENPG) in a primary care setting in an urban area.

PATIENTS AND METHODS

During 1994 clinical information concerning a group of patients attended in the primary care setting of an area of Barcelona city was recorded prospectively on a computerised information sheet.

RESULTS

483 patients were evaluated (age: 68.9 +/- 0.5 years; males: 43.3%; 13.1 +/- 0.4 years of NIDDM evolution), 303 treated without insulin and 180 with insulin. A 37.9% of patients never had carried out self-glucose monitoring and the patients with insulin practised it more frequently (p = 0.03). Levels of basal glycemia, HbA1c' total and HDL cholesterol, basal triglycerides and body mass index were poor in 65.8%, 57.3%, 25.2%, 48.2%, 20.7% and 59.6% of the patients, respectively. Retinopathy and microalbuminuria have never been screened in 32.9% and 95.4% of the patients, respectively: in both cases the situation was worst in those without insulin (p = 0.00 and p = 0.02, respectively). Amaurosis was present in 3.9% of patients, clinical neuropathy in 16.8%, clinical peripheral neuropathy in 19.0%, ischemic heart disease in 13.3%, lower limb amputations in 2.1% and a stroke history in 10.1%. All these complications and the level of HbA1c were higher in patients with insulin (p < 0.05).

CONCLUSIONS

The attainment of the recommendations of ENPG is scarce at the primary care level. Patients had insufficient blood glucose self-monitoring, metabolic control and screening for retinopathy and microalbuminuria.

Effects of insulin administration on beta-cell function in subjects at high risk for type I diabetes mellitus

The aim of the study was to determine the appropriate dose of subcutaneous insulin to induce "beta-cell rest" without any hypoglycemic risk, as the first stop in the investigation of its potential effect in preventing or delaying clinical diabetes mellitus onset in high-risk subjects. Four subjects at high risk for type I diabetes mellitus (first-degree relatives, islet cell antibodies (ICA)-positive, and with diminished first-phase insulin secretion) were compared with four healthy individuals. After hospitalization, urinary C-peptide excretion (UCP) and 24-hour serum profiles for glucose were measured before and after administration of NPH insulin 0.1, 0.2, and 0.3 U x kg body weight per day subcutaneously in a single dose on 4 consecutive days. After insulin 0.1 U x kg body weight, a significant inhibition of endogenous insulin secretion was observed in high-risk subjects, but not in control subjects. There was no further inhibition when a higher insulin dose (0.2 and 0.3) was administered. A sustained beta-cell rest was obtained after 3, 6, and 12 months of treatment with 0.1 U x kg body weight per day as outpatient therapy in high-risk subjects. With this dose, no subject developed hypoglycemia (plasma glucose <50 mg/dL), whereas this adverse effect was detected after 0.2 and 0.3 U x kg body weight in both groups. In conclusion, our results indicate that administration of NPH insulin 0.1 U x kg bodyweight per day induces beta-cell rest without the undesirable effect of hypoglycemic episodes. This is a preliminary study to investigate the potential beneficial effect of insulin in preventing or delaying type I diabetes mellitus in subjects at high risk for the disease.

[Retinopathy in patients with insulin-dependent diabetes mellitus of short duration]

To evaluate the role of metabolic control at the beginning of insulin-dependent diabetes mellitus (IDDM) in the development of diabetic retinopathy (DR) a cross-sectional study was performed with a retrospective analysis of 24 patients followed for at least seven years. The following parameters were investigated: 1) At IDDM diagnosis, age, sex, metabolic control (basal serum glucose, HbA1, cholesterol, triglycerides) and endogen insulin secretion (EIS). 2) At one year in the follow-up: EIS. 3) Since IDDM diagnosis and every 3-4 months: body mass index, dose and pattern of insulin administration and metabolic control. 4) At seven years in the follow-up: direct ophthalmoscopy, fluorescein angiography, microalbuminuria and blood pressure. In the seventh year of follow-up five patients (23.8%; 95% CI: 8.2%-47.2%) developed changes in fluorescein angiography secondary to IDDM. Compared with patients with normal fluorescein angiography their metabolic control was poorer (mean HbA1--seven years--: 11.7 +/- 0.5 versus 9.8 +/- 0.3%; p = 0.01); mean basal glycemia--seven years--: 214 +/- 13.3 versus 174 +/- 7.7 mg/dl; p = 0.03) and their systolic blood pressure (SBP) higher (124 +/- 5.5 versus 111 +/- 2.8 mmHg; p = 0.04). Logistic regression revealed that mean HbA1 values for seven years was the only independent risk factor significantly associated with the development of DR (p = 0.04). The conclusion is that in patients with IDDM of short duration, the development of DR is associated with a deficient glucose control and a higher SBP.

[Insulin treatment in diabetes mellitus type II: the usefulness of the breakfast test]

BACKGROUND

Insulin treatment in patients with type-II diabetes mellitus (DMII) is normally undertaken by clinical criteria. The aim of the present was to study the efficacy of a standard mixed meal (breakfast test) to predict the need for insulin therapy to thereby evaluate whether it is possible to obtain more objective criteria for the indication of insulin treatment.

METHODS

Fifty-six patients with DMII were studied to evaluate the need for insulin therapy over a one-year period. Serum glucose and basal C peptide and their maximum values were determined in all the patients following stimulation with the breakfast test. Insulin treatment was initiated according to exclusively clinical criteria during admission. The patients were followed as out patients for a minimum of 3 months. Treatment at the end of follow up (insulin or no insulin) was evaluated and the results of the test were retrospectively analyzed.

RESULTS

The basal C peptide (BCP) values were significantly lower in the individuals requiring insulin in comparison to those who did not require insulin (mean +/- SD 0.64 +/- 0.28 versus 1.18 +/- 0.41 nmol/l, p < 0.0001) similar to what was found with the stimulated maximum C peptide values (MCP) (1.48 +/- 0.77 versus 2.49 +/- 0.63 nmol/l, p < 0.0001). On considering a BCP of less than 0.9 nmol/l for the patients with insulin treatment the sensitivity of BCP was 83.6% and the specificity 78.9%. For a BCP value of less than 1.9 nmol/l sensitivity was 77.7% and specificity 78.9%. Using the values together, sensitivity was 66.6% and specificity 84.4%.

CONCLUSIONS

The breakfast test is useful to indicate the need for insulin therapy in patients with type II diabetes mellitus but is not more useful than a determination of isolated basal C peptide.

[Measurement of vibratory threshold in the diagnosis of diabetic neuropathy]

The usefulness of the quantitative measurement of vibration perception threshold (VPT) was assessed by a biothesiometer in the diagnosis of peripheral neuropathy in 36 patients with type I diabetes mellitus. The study included: a) clinical assessment (history and neurological examination); b) measurement of VPT at right metatarsus, right pretibial area and right metacarpus; c) electromiographical study (right peroneal, posterior tibial, right sural, right medial plantar); d) assessment of the autonomous nervous system (sympathetic and parasympathetic indexes); e) metabolic assessment (HbA1c at study and mean HbA1c in the previous year). The prevalence of peripheral neuropathy was 38%. VPT at metatarsal region in diabetic patients was higher than in controls (p < 0.05) and a positive correlation with evolution time of disease at metatarsal region (p < 0.05) and tibia (p < 0.05) was observed. Clinical symptoms and changes at examination correlated with VPT at metatarsus (p < 0.05) and tibia (p < 0.05). No relationship was observed between VPT and metabolic control. In conclusion, vibration threshold increases with evolution time in diabetes, but it was not influenced by metabolic control. Its measurement by a simple method, such as biothesiometer, could be useful in diagnosing peripheral neuropathy in clinically asymptomatic patients.

Diabetes mellitus in patients with liver cirrhosis

In spite of the high prevalence of diabetes mellitus (DM) in patients with liver cirrhosis (LC) few studies have focused on the clinical implications of this association. We investigated the clinical and pancreatic-endocrine features of 34 patients who developed DM after LC (Group I). Results were compared with 34 carefully matched patients with only Type II DM (Group II). A standard meal test was performed in 26 patients with normal renal function from each group to assess beta-cell function. Group I patients, less frequently had retinopathy (14.7% vs. 45.5%, P < 0.05) and a family history of diabetes (23.5% vs. 58.8%, P < 0.01). Group I patients also showed signs of enhanced insulin resistance, reflected by higher insulin dose requirements in insulin-treated patients (0.87 +/- 0.10 vs. 0.62 +/- 0.05 IU/kg/day, P < 0.01) and increased basal C-peptide values (0.88 +/- 0.06 vs. 0.68 +/- 0.07 pmol/l, P < 0.05, respectively) than those in Group II. These results suggest that several clinical features, probably related to the hepatopathy, define DM occurring in patients with LC.

Microalbuminuria development in short-term IDDM

To assess risk factors associated with microalbuminuria development in short-term evolution insulin-dependent diabetes mellitus (IDDM) we undertake a cross-sectional study with retrospective examination of the 34 patients diagnosed with IDDM between 1982 and 1983 and followed up for at least 7 years in an outpatient endocrinology clinic.

MAIN MEASURES

(1) At IDDM diagnosis: age, sex, parameters of metabolic control (fasting glycemia, HbA1), islet-cell antibodies, insulin autoantibodies, endogenous insulin secretion (EIS) and HLA type. (2) At 1 year evolution: EIS re-evaluation. (3) From IDDM diagnosis (every 3-4 month): body mass index, insulin schedule and dose, and parameters of metabolic control. (4) At 7-year evolution: 24-h urinary albumin excretion (UAE) and arterial blood pressure measurements on two consecutive outpatient controls. Microalbuminuria was defined as UAE above 30 micrograms/min on the two consecutive measurements. After 7-year follow-up, 8 (23.5%; 95% Cl: 9.3 to 37.7%) patients developed microalbuminuria. Their metabolic control was worse (7 years mean HbA1: 10.7 vs. 9.7%; P = 0.04) and 1 year EIS lower (1.9 vs. 7.6 ng/ml.10 min; P = 0.03) than in normoalbuminuric patients. They also had higher prevalence of 'high-normal' arterial blood pressure (P = 0.03) and diabetic retinopathy (P = 0.01) than normoalbuminuric patients did. Stepwise logistic regression analysis showed that diabetic retinopathy was the only independent and significant risk factor related to microalbuminuria development (P = 0.01). We conclude that in subjects with short-term evolution IDDM, microalbuminuria development was associated with glycemic control, EIS and arterial blood pressure levels, however the strongest association was found with diabetic retinopathy occurrence.

Deleterious effect of dithizone-DMSO staining on insulin secretion in rat and human pancreatic islets

Dithizone (DTZ) is a selective stain for pancreatic islets which facilitates their identification, being of special interest in human islet isolation assessment. Nevertheless, there are few studies concerning its potential toxic effects on islet function. In our study, we have evaluated the effects of DTZ (dissolved in dimethyl sulfoxide [DMSO] 1% w/v) at three different concentrations (2, 10, and 100 micrograms/ml) on insulin response to glucose in human and rat islets. Likewise, we studied the effect of incubation time, in the presence of DTZ at the above-mentioned concentrations, on insulin release. Only when DTZ was employed at low concentrations and for a short period of incubation (10 min) was there no impairment of pancreatic islet function. Moreover, even at this low concentration, DTZ became deleterious for islet function when the incubation period with the dye was prolonged for 30 min. Culture (24 h) of previously stained islets produced a partial recovery of insulin response. In conclusion, our findings indicate (a) DTZ should not be employed to collect islets for functional studies because of its deleterious effect on beta-cell function, (b) DTZ's deleterious effects on beta-cell function should be considered if this dye is used to purify islets by fluorescence-activated cell sorting for transplantation.

[Isolated ACTH deficiency]

The isolated ACTH deficiency is a scarcely diagnosed disease of heterogeneous nature. Two patients with isolated deficiency of ACTH in whom the initial diagnosis was of primary suprarrenal failure are reported. In the first case this diagnosis was performed after hospital admission for deterioration of the level of consciousness and the development of an acute suprarrenal crisis in the course of nosocomial pneumonia. In the second case the clinical manifestations began as weakness, anorexia, weight loss and lymphocytosis with eosinophilia. In both patients an increase in the thyrotropic hormone was detected leading to suspicion of the existence of associated primary hypothyroidism. Finally, several studies were carried out (basal measurements of cortisol and ACTH, stimulation with continual perfusion of ACTH, insulinic hypoglycemia, global study of adenohypophysary function, ACTH CRF release factor test, computerized tomography of the pituitary region) in both patients leading to the definitive diagnosis of isolated ACTH deficiency of idiopathic cause of possible pituitary origin without the existence of other associated hormonal deficiencies.