The Hybrid Closed-Loop System Tandem t:slim X2™ with Control-IQ Technology: Expert Recommendations for Better Management and Optimization

Technological advances in the management of diabetes, especially type 1 diabetes (T1D), have played a main role in significantly improving glycemic control of these patients in recent years. Undoubtedly, the most important advance has been the commercialization of hybrid closed-loop systems (HCL). Their effectiveness places them in the different guidelines from scientific societies as the gold standard for the treatment of people with T1D. However, obtaining the maximum performance from these systems requires a degree of expertise from the professionals who care for these patients. Specifically, the Tandem X2:slim with Control-IQ technology system, due to its features and configuration options and adjustments, allows T1D patients to better adapt the management of diabetes to multiple circumstances in their day-to-day life. It is necessary, however, to follow a systematic process to start the system and also for the subsequent follow-up, which allows its optimization in the shortest possible time. This expert recommendation reviews the main features of this HCL system, suggesting how to implement it and optimize its use after gaining experience treating many patients.

Association between gut microbiota and psychiatric disorders: a systematic review

Introduction

In recent years, it has been described that the dysbiosis of the intestinal microbiota plays a transcendental role in several pathologies. In this sense, the importance of the gut microbiota in the gut-brain axis, with a bidirectional communication, has been demonstrated. Furthermore, the gut microbiota has been linked with mood disorders and neuropsychiatric disorders.

Methods

A systematic review of two databases - PubMed and Scopus - was carried out following PRISMA guidelines. We included original studies in humans with a control group published in the last 11 years, which were assessed by the Critical Appraisal Skills Program (CASP) to confirm their quality. Eighteen articles met all the selection criteria.

Results

A review of the articles revealed an association between psychiatric disorders and different bacterial phyla. The studies we have reviewed have demonstrated differences between subjects with psychiatric disorders and controls and highlight a clear relationship between depression, stress, autism spectrum disorder (ASD), psychotic episodes, eating disorders, anxiety and brain function and the gut microbiota composition.

Conclusion

A reduction of fermentative taxa has been observed in different psychiatric disorders, resulting in a decrease in the production of short-chain fatty acids (SCFAs) and an increase in pro-inflammatory taxa, both of which may be consequences of the exacerbation of these pathologies.

Effect of perceived stress, concern about hypoglycaemia and level of knowledge of management of the disease on glycaemic control in type 1 diabetes mellitus

AIMS AND OBJECTIVES

To evaluate perceived stress, concern about hypoglycaemia and the level of knowledge of management of the disease in patients with type 1 diabetes mellitus and their relationship with glycaemic control, gender and age.

BACKGROUND

Perceived stress and concern about hypoglycaemia are significant obstacles to achieving adequate glycaemic control in patients with type 1 diabetes mellitus, and notably influence management of the disease itself.

MATERIAL AND METHODS

A cross-sectional study was carried out in 193 adult patients with type 1 diabetes mellitus. Study quality was scored using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist for cohort studies. Glycaemic control was evaluated by number and type of hypoglycaemic event and glycosylated haemoglobin. Questionnaires about hypoglycaemia concern (HFS II), perceived stress (PSS), unrecognised hypoglycaemia (Clarke Test) and level of knowledge of the disease were completed.

RESULTS

Perceived stress was significantly associated with glycosylated haemoglobin (p < 0.001) and concern about hypoglycaemia (p < 0.037). With respect to level of knowledge, we observed that an advanced level was associated with lower glycosylated haemoglobin (p < 0.001), number (p < 0.001) and type (p < 0.001) of hypoglycaemic episode, and less perceived stress (p = 0.006). In addition, age was negatively correlated with perceived stress (p < 0.030) and positively correlated with the number of unrecognised hypoglycaemic episodes (p < 0.002), which was associated, in turn, with a higher number of daily glycaemia tests (p < 0.037) and concern about hypoglycaemia (p < 0.006).

CONCLUSION

In type 1 diabetes mellitus, perceived stress can negatively influence glycaemic control and concern about hypoglycaemia, and level of knowledge about the condition has a bearing on glycosylated haemoglobin levels, perceived stress and number and type of hypoglycaemic events. In addition, higher age is associated with more frequent unrecognised hypoglycaemic events.

RELEVANCE TO CLINICAL PRACTICE

It is essential to identify and address the psychological needs of patients with type 1 diabetes mellitus with the aim of achieving an adequate management of the disease itself and generating a change in future intervention strategies.

The Role of Mitochondrial Dynamic Dysfunction in Age-Associated Type 2 Diabetes

Mitochondrial dynamics, such as fusion and fission, play a critical role in maintaining cellular metabolic homeostasis. The molecular mechanisms underlying these processes include fusion proteins (Mitofusin 1 [MFN1], Mitofusin 2 [MFN2], and optic atrophy 1 [OPA1]) and fission mediators (mitochondrial fission 1 [FIS1] and dynamin-related protein 1 [DRP1]), which interact with each other to ensure mitochondrial quality control. Interestingly, defects in these proteins can lead to the loss of mitochondrial DNA (mtDNA) integrity, impairment of mitochondrial function, a severe alteration of mitochondrial morphology, and eventually cell death. Emerging evidence has revealed a causal relationship between dysregulation of mitochondria dynamics and age-associated type 2 diabetes, a metabolic disease whose rates have reached an alarming epidemic-like level with the majority of cases (59%) recorded in men aged 65 and over. In this sense, fragmentation of mitochondrial networks is often associated with defects in cellular energy production and increased apoptosis, leading, in turn, to excessive reactive oxygen species release, mitochondrial dysfunction, and metabolic alterations, which can ultimately contribute to β-cell dysfunction and insulin resistance. The present review discusses the processes of mitochondrial fusion and fission and their dysfunction in type 2 diabetes, with special attention given to the therapeutic potential of targeting mitochondrial dynamics in this complex metabolic disorder.

Psychometric properties of a questionnaire to measure adherence to treatment in patients with type 1 diabetes mellitus

Aim

To validate the psychometric properties of a questionnaire to measure adherence to treatment among people with type 1 diabetes mellitus and to evaluate its relationship with metabolic control.

Design

A cross‐sectional study of 167 adult people with type 1 diabetes mellitus recruited from the Endocrinology Service of University Hospital Doctor Peset (Spain).

Methods

The validity of the content, construct and reliability of the instrument were evaluated and the results correlated with levels of glycosylated haemoglobin.

Results

The questionnaire was composed of 25 items and 5 dimensions, with a score of 25–150 points and an internal consistency of 0.92, according to Cronbach's coefficient α. The content of validity ratio and the construct (exploratory functional analysis, Kaiser–Meyer–Olkin index and Barlett's spherical test) were adequate. We observed a significant correlation between glycosylated haemoglobin levels and treatment adherence.

Conclusion

The questionnaire to measure adherence to treatment in type 1 diabetes mellitus is consistent, reliable and valid, showing an excellent association with degree of metabolic control.

Institutional Experience With New Antidiabetic Drugs in Kidney Transplant

BACKGROUND

The recent introduction of new antidiabetic drugs, analogs of glucagon-like peptide-1 (GLP-1) and sodium-glucose cotransporter 2 inhibitors, has shown excellent results in the management of patients with diabetes with chronic kidney disease. However, documented results of these medications in the population that has undergone kidney transplant are sparse. We report our institutional experience with them, including occurrence of side effects and possible interactions with immunosuppressive medications.

METHODS

A retrospective analysis of 15 patients (10 with diabetes and 5 without diabetes but with obesity) managed with these medications was carried out in the kidney transplant unit of Hospital Doctor Peset during the year 2019. Data acquired at baseline and 3, 6, and 12 months were analyzed.

RESULTS

The median hemoglobin A1c at baseline was 6.7 (interquartile range [IQR] = 5.8-8.2) and at 12 months it was 6 (IQR = 5.3-8.1, P = .96). The mean weight difference at 12 months was a loss of 7.2 ± 6 kg; median body mass index at baseline was 31.2 kg/m² (IQR = 29.7-35.5) and 29.5 kg/m² (IQR = 27.6-31.6, P = .01) at 12 months. In addition to weight loss, a reduction in insulin and oral antidiabetic drug requirements was observed. No significant changes were detected in serum creatinine or proteinuria values and the immunosuppressant levels remained stable. No acute rejection episodes were observed.

CONCLUSION

Based on our experience, the new antidiabetic drugs are safe, with no significant changes in renal function or immunosuppressant levels or clinically important adverse effects.

Association of erythrocyte deformability with red blood cell distribution width in metabolic diseases and thalassemia trait

Increased red blood distribution width (RDW) in anemia is related to disturbances in the cellular surface/volume ratio, usually accompanied by morphological alterations, while it has been shown in inflammatory diseases that the activity of pro-inflammatory cytokines disturbing erythropoiesis increases RDW. Recently it has been reported that higher RDW is related with decreased erythrocyte deformability, and that it could be related with the association of RDW and increased risk of cardiovascular diseases. In order to analyze the influence of morphological alterations and proinflammatory status on the relationship between RDW and erythrocyte deformability, we analyzed erythrocyte deformability along with RDW and other hematological and biochemical parameters in 36 α-thalassemia, 20 β-thalassemia, 20 δβ-thalassemia trait carriers, 61 metabolic syndrome patients and 76 morbidly obese patients. RDW correlated inversely with erythrocyte deformability in minor β-thalassemia (r =-0.530, p <  0.05), and directly in both metabolic syndrome and morbidly obese patients (ρ= 0.270, p <  0.05 and ρ= 0.258, p <  0.05, respectively). Minor β-thalassemia is often accompanied by more marked cell-shaped perturbations than other thalassemia traits. This could be the reason for this negative association only in this setting. Higher anisocytosis seems to be associated with greater morphologic alterations (shape/volume), which reduce erythrocyte deformability. The proinflammatory profile in metabolic patients can be related to the positive association of RDW with erythrocyte deformability found in these patients. However, further research is needed to explain the mechanisms underlying this association.

Association of metabolic syndrome and its components with hyperuricemia in a Mediterranean population

Several studies have found an association between hyperuricemia and metabolic syndrome (MS), although there are discrepancies as to which MS components play a pivotal role in this association. We aimed to investigate the association between serum uric acid (SUA) levels and MS in a Mediterranean population (eastern Spain). We performed a case-control study of 71 patients with MS and 122 healthy controls. MS was defined according to the revised National Cholesterol Education Program Adult Treatment Panel III modified criteria. Hyperuricemia was defined as SUA levels >6.55 mg/dL. We determined biochemical, lipidic and inflammatory parameters along with uric acid. Patients with MS showed a higher risk of hyperuricemia than those without MS (OR: 2.87 95% CI: 1.48- 5.55; p = 0.002). In turn, the unadjusted logistic regression analysis showed that hyperuricemia is associated with a higher risk of presenting all the MS components, except hypertension; i.e., hypertriglyceridemia, low HDL-cholesterol, abdominal obesity and glucose intolerance were predictors for hyperuricemia (OR: 3.15, 95% CI: 1.61- 6.15, p = 0.001; OR: 4.07, 95% CI: 1.77- 9.33, p = 0.001; OR: 2.81, 95% CI: 1.41- 5.58, p = 0.003 and OR: 2.82, 95% CI: 1.46- 5.45, p = 0.002 respectively). The adjusted logistic regression analysis revealed that only low HDL-cholesterol and glucose intolerance were independent predictors for hyperuricemia (OR: 2.71, 95% CI 1.06- 6.97, p = 0.038; OR: 2.14, 95% CI 1.01- 4.56, p = 0.049, respectively). In our geographical area, the patients with MS showed a nearly 3-fold risk of hyperuricemia than those without. Among all the MS components, low-HDL-cholesterol and high glucose independently increased more than twice the risk of hyperuricemia, and are the pivotal components involved in hyperuricemia.

Red blood cell distribution width is not related with inflammatory parameters in morbidly obese patients

OBJECTIVE

Red blood cell distribution width (RDW) is a hematological parameter that has been studied in several clinical settings and has been found to be related to both anemia and inflammatory status. As obesity is related to increased inflammatory pattern, we aimed to analyze the RDW in this setting.

METHODS

We determined hematological and inflammatory parameters in morbidly obese patients before bariatric surgery (n=142) and normo-weight controls (n=144).

RESULTS

RDW was higher in patients than in controls (p<0.001), along with C-reactive protein (p<0.001) and fibrinogen, (p<0.001) while hemoglobin (p=0.026), serum iron (p<0.001), MCH (p=0.002) and MCHC (p<0.001) were lower in morbidly obese patients. The logistic correlation analysis revealed that only low serum iron (<62 μg/dL) and MCH (<28.14 pg) levels were associated with RDW>14% (OR 7.61, 95% CI: 1.93-30.04, p=0.004; OR 5.67, 95% CI: 1.98-16.24, p=0.001; respectively).

CONCLUSIONS

These data indicate that the elevated RDW in morbidly obese patients reflects a mild red blood cell hypochromia that does not relate to inflammatory parameters, but to hyposideremia and, consequently, to lower erythrocyte indices, possibly as a result of being on a very low-calorie diet before bariatric surgery. Therefore, RDW should not be considered as an inflammatory marker in this clinical setting.

Association of serum retinol binding protein 4 with atherogenic dyslipidemia in morbid obese patients

Retinol binding protein 4 (RBP4) is an adipokine that may contribute to the development of insulin resistance. However, how this adipokine is affected and its possible involvement in lipid metabolism in obese patients with varying degrees of insulin resistance is yet to be determined. A total of 299 middle-aged morbid obese patients (BMI>40 kg/m(2)) were divided in euglycemic, metabolic syndrome or type 2 diabetic. Anthropometric measurements, biochemical variables and systemic RBP4 levels were determined. RBP4 levels were significantly higher in patients with metabolic syndrome and type 2 diabetes than in euglycemic subjects (42.9±14.6; 42.3±17.0 and 37.4±11.7 µg/ml, respectively) and correlated with triglycerides but not with those of HOMA-IR in the whole population. The multivariate regression model revealed that triglycerides were the strongest predictor of systemic RBP4 levels. Analysis of lipoprotein subfractions in a subpopulation of 80 subjects showed an altered profile of insulin resistant states characterized by higher VLDL, sdLDL and small HDL percentages and lower large HDL percentage. Although RBP4 levels correlated significantly with LDL particle size and small HDL percentage, the latter parameter was independently associated only with RBP4. Our study reveals that systemic RBP4 levels could play an important role in lipid metabolism in morbid obesity, increasing triglyceride levels and contributing to the formation of small HDL.

Relation between lipoprotein subfractions and TSH levels in the cardiovascular risk among women with subclinical hypothyroidism

OBJECTIVE

Subclinical hypothyroidism (SCH) is a common condition associated with increased cardiovascular risk. A standard treatment is yet to be established, as there is no consensus on the TSH cut-off values which should be used as indicators. Thus, the aim of this study was to assess cardiovascular risk in patients with SCH and to differentiate it according to TSH levels.

DESIGN

This was an observational study conducted in an academic medical centre.

PATIENTS

The study population consisted of 95 middle-aged women recently diagnosed with SCH and 65 euthyroid controls.

MEASUREMENTS

We measured anthropometric parameters, lipid cardiovascular risk markers and lipoprotein subclasses of HDL and LDL.

RESULTS

Patients with SCH exhibited a significant increase in triglycerides and atherogenic index of plasma and a significant reduction in HDL-cholesterol with respect to the control group after adjusted by age and BMI. A similar lipid profile was observed in both SCH groups. However, patients with TSH levels higher than 10 mIU/l showed a significant reduction in LDL particle size, which was associated with a higher prevalence of atherogenic pattern B.

CONCLUSIONS

Our findings indicate that cardiovascular risk is affected in patients with TSH levels over 10 mIU/l, who have a lipid profile characteristic of atherogenic dyslipidemia.

Homocysteine levels in morbidly obese patients: its association with waist circumference and insulin resistance

The association between morbid obesity and hyperhomocysteinemia (HH) remains controversial and the nature of this relationship needs to be clarified as several metabolic, lipidic, inflammatory and anthropometric alterations that accompany morbid obesity may be involved. In 66 morbidly obese patients, 47 women and 19 men aged 41 ± 12 years and 66 normo-weight subjects, 43 women and 23 men, aged 45 ± 11 years, we determined homocysteine (Hcy) levels along with lipidic, anthropometric, inflammatory and insulin resistance markers. In addition, we investigated the effect of Metabolic Syndrome (MS) and its components on Hcy levels. Obese patients had statistically higher Hcy levels than controls: 12.76 ± 5.30 μM vs. 10.67 ± 2.50 μM; p = 0.006. Moreover, morbidly obese subjects showed higher waist circumference, glucose, insulin, HOMA, leptin, triglycerides, fibrinogen, C reactive protein (CRP) (p < 0.001, respectively), and lower vitamin B12 (p = 0.002), folic acid and HDL-cholesterol (p < 0.001, respectively). In the multivariate regression analysis, waist circumference, glucose, leptin and folic acid levels were independent predictors for Hcy values (p < 0.050). When obese patients were classified as having MS or not, no differences in Hcy levels were found between the two groups (p = 0.752). Yet when we analysed separately each MS component, only abdominal obesity was associated with Hcy levels (p = 0.031). Moreover when considering glucose >110 mg/dL (NCEP-ATPIII criteria) instead of glucose intolerance >100 mg/dl (updated ATPIII criteria), it also was associated with HH (p = 0.042). These results were confirmed in the logistic regression analysis where abdominal obesity and glucose >115 mg/dL constitute independent predictors for HH (OR = 3.2; CI: 1.23-13.2; p = 0.032, OR: 4.6; CI: 1.7-22.2; p = 0.016, respectively). The results of our study indicate that increased Hcy levels are related mostly with abdominal obesity and with insulin resistance. Thus, HH may raise atherothrombotic and thromboembolic risk in these patients.

Association between hemorheological alterations and metabolic syndrome

The contribution of hemorheological alterations in the prothrombotic condition in patients with metabolic syndrome (MS) remains a question of debate. We aimed to determine the association between MS and hemorheological parameters by means of a case-control study in 61 MS patients and 89 controls without MS. We determined blood viscosity at 230 s(-1) (Brookfield DVIII viscosimeter); plasma viscosity (Fresenius capillary plasma viscosimeter); erythrocyte aggregation at stasis and 3 s(-1) (MA-1 erythrocyte aggregometer); erythrocyte deformability (Rheodyn SSD at shear stresses of 12, 30 and 60 Pascals) and fibrinogen, along with anthropometric, lipidic and inflammatory parameters. MS patients showed increased blood viscosity (p = 0.018), plasma viscosity (p < 0.001), fibrinogen (p < 0.001), erythrocyte aggregation (p < 0.001), and decreased erythrocyte deformability (p = 0.033). In the multivariate regression analysis, fibrinogen and triglycerides predicted plasma viscosity and erythrocyte aggregability, whereas erythrocyte deformability was associated with alterations in the hydrocarbonate metabolism. Blood viscosity related to abdominal obesity. The logistic regression analysis revealed that of all the MS components, only hypertriglyceridemia independently predicts plasma hyperviscosity (OR 3.75 CI 1.44-9.77 p = 0.007) and erythrocyte hyperaggregability (OR 2.41 CI 1.00-5.80 p = 0.050). Erythrocyte hyperaggregability (EA > 8.23) and hyperfibrinogenemia (fibrinogen > 358 mg/dL) were independent predictors of MS: OR 3.34, 95% CI 1.40-7.93, p = 0.006 and OR 2.42 95% CI 1.04-5.66, p = 0.041, respectively. We conclude that MS is associated with an altered hemorheological profile related to inflammatory, lipidic and glucose intolerance parameters which could favor the development of thrombo-embolic and athero-thrombotic events in MS patients.

Effect of weight loss on C3 and C4 components of complement in obese patients

BACKGROUND

Circulating C3 levels are elevated in obese patients, but how this factor is affected after weight loss through diet is a question that is yet unanswered. Therefore, the aim of this study was to evaluate the effects of weight loss on lipid and hydrocarbonated metabolism parameters and on the levels of C3 and C4 components of complement in obese patients.

DESIGN

This is a longitudinal intervention study based on a 6-week very low-calorie diet (VLCD), a liquid formula of 603 kcal/day. A total of 131 middle-aged patients were distributed among grades II, III and IV of obesity. Anthropometric parameters, total cholesterol, triglycerides, high-density lipoprotein cholesterol, LDLc, apolipoproteins A-I and B-100, glucose, insulin, HOMA-IR and C3 and C4 levels were evaluated at baseline and after 6 weeks of intervention.

RESULTS

After VLCD, the moderate weight loss was accompanied by a significant reduction in C3 levels in grade III and grade IV patients (10.2% and 15.4%, respectively; P < 0.001). C4 levels were not altered. Adherence to the diet improved anthropometric parameters and was accompanied by a significant decrease in all lipid profile parameters (P < 0.001). In addition, weight loss was associated with an improvement in hydrocarbonated metabolism as shown by the decrease in glucose levels and HOMA-IR (P < 0.01).

CONCLUSIONS

Our findings show that in severely obese patients following a VLCD for 6 weeks produces reductions in factor C3, a biomarker of cardiovascular disease, and a significant improvement in some features of metabolic syndrome. In this way, the abovementioned diet may represent an effective strategy for treating obesity and related cardiovascular risk factors.

Erythrocyte deformability in morbid obesity before bariatric surgery. Influence of abdominal obesity

Although there are several studies dealing with erythrocyte deformability (ED) in obese patients, research on this topic in morbidly obese subjects is scarce. In these studies ED seems to be decreased, although the cause remains unknown. A case-control study in 76 morbid obese subjects (23 women and 53 men, aged 44 ± 13 years) and in 79 normal-weight controls (30 women and 49 men, aged 43 ± 13 years) was undertaken. ED has been determined by ektacytometric techniques in a Rheodyn SSD, by means of the elongation index (EI) at 12, 30 and 60 Pascals, along with anthropometric, lipidic, metabolic and inflammatory parameters. EI was statistically lower in morbidly obese subjects than in controls at all the shear stresses tested (EI12: 47.3 ± 2.14 vs. 47.9 ± 2.07; p = 0.047, EI30: 52.16 ± 2.1 vs. 53.12 ± 1.4; p = 0.007, EI60: 53.9 ± 2.4 vs. 55.2 ± 2.50; p = 0.001) as were anthropometric lipidic and inflammatory parameters (p < 0.001). In the bivariate correlation EI60 correlated negatively with most anthropometric, lipidic and inflammatory parameters. However, in the multivariate analysis, the case-control status was not significantly associated with EI60 and only triglycerides, glucose, hs-CRP and waist circumference were independently associated with EI60, constituting independent predictors of altered ED although, waist circumference, showed the highest statistical significance (p = 0.007). ED is decreased in morbidly obese subjects associated with insulin resistance and inflammation parameters although abdominal obesity seems to be of paramount importance in altering this rheological parameter.

Oxidative stress, endothelial dysfunction and atherosclerosis

This review focuses on the role of oxidative processes in atherosclerosis and the cardiovascular diseases (CVD) that can arise as a result. Atherosclerosis represents a state of heightened oxidative stress characterized by lipid and protein oxidation in the vascular wall. Overproduction of reactive oxygen species (ROS) under pathophysiologic conditions forms an integral part of the development of CVD, and in particular atherosclerosis. Endothelial dysfunction, characterized by a loss of nitric oxide (NO) bioactivity, occurs early on in the development of atherosclerosis, and determines future vascular complications. Although the molecular mechanisms responsible for mitochondria-mediated disease processes are not clear, oxidative stress seems to play an important role. In general, ROS are essential to the functions of cells, but adequate levels of antioxidant defenses are required in order to avoid the harmful effects of excessive ROS production. In this review, we will provide a summary of the cellular metabolism of reactive oxygen species (ROS) and its role in pathophysiological processes such as atherosclerosis; and currently available antioxidants and possible reasons for their efficacy and inefficacy in ameliorating oxidative stress-mediated diseases.

Small and dense LDL in familial combined hyperlipidemia and N291S polymorphism of the lipoprotein lipase gene

There is a predominance of small and dense LDL cholesterol particles in familial combined hyperlipidemia (FCH). The lipoprotein lipase gene could exert an influence in these circumstances.

To study the relationship of pattern B LDL and lipids with N291S polymorphism of lipoprotein lipase (LPL) in FCH patients.

Lipid profile, apolipoproteins, diameter of LDL and N291S polymorphism were determined in 93 patients with FCH and 286 individuals from the general population.

FCH patients with N291S polymorphism showed a lower mean diameter of LDL. FCH patients with pattern B LDL showed higher concentrations of triglycerides, VLDLc, non-HDLc and apo B100 and lower levels of HDLc than those with pattern A. Of FCH patients with polymorphism 87.5% presented pattern B and 12.5% pattern A, while patients without polymorphism presented pattern A in 69.2% cases and pattern B in 30.8% cases, with differences being statistically significant (p < 0.004). The prevalence of this mutation in our FCH patients was 9.7%.

The prevalence of N291S mutation in our FCH patients was similar to the 9.3% described in Dutch FCHL patients but clearly higher than the 2–5% described for other Caucasian populations. No polymorphism was found in our general population sample. FCH patients with phenotype B of LDL possessed an atherogenic lipid profile. The relationship between small and dense LDL and the presence of the N291S mutation may identify patients with high cardiovascular risk.

Erythrocyte membrane phosphatidylserine exposure in obesity

It has been suggested that increased erythrocyte membrane phosphatidylserine (PS) exposure could contribute to hypercoagulability and hemorheological disturbances in obesity. The aim of our study was to evaluate PS exposure in obese patients and in a control group and to correlate this with hemorheological properties, i.e., erythrocyte aggregability (EA) and deformability, and to evaluate the effect of weight loss on these parameters. An anthropometric and analytical evaluation was performed at baseline and after 3 months on a diet (very low-calorie diet for 4 weeks and low-calorie diet for 2 months) on 49 severe or morbid obese patients (37 women, 12 men) and 55 healthy volunteers (39 women, 16 men). PS exposure on erythrocyte membrane was performed by flow cytometry. Erythrocyte aggregation was measured using the Myrenne MA(1) and the Sefam aggregometer. Erythrocyte deformability was determined in a stress diffractometer. Prothrombin fragment F1+2 (F1+2) was determined as a marker of the hypercoagulable state, and plasma malondialdehyde (MDA) as an indicator of oxidative stress. Obese patients had a higher EA index, higher PS exposure on erythrocyte membranes and higher levels of MDA and F1+2. The differences in erythrocyte aggregation and F1+2 between obese patients and the control group were maintained after adjusting for PS exposure. After 3 months of diet, a significant reduction in PS exposure on erythrocyte membrane was observed. Obese patients show increased PS exposure on erythrocyte membrane, with no effect on rheological properties. Increased PS exposure could contribute to hypercoagulability in these patients. Weight loss obtained with diet treatment reduces PS exposure on erythrocyte membrane.

Activated protein C levels in obesity and weight loss influence

Obesity is associated with a high risk of cardiovascular events. Several haemostatic disturbances which could contribute to this increased risk have been described in obesity; nevertheless, the state of coagulation inhibitors has been scarcely studied in these patients. The aim of the present study was to compare activated protein C levels in obese patients and in a control group, and to evaluate the effect of weight loss. In 67 severe or morbid obese patients, an evaluation was performed at baseline and 3 months after diet. The same determinations were performed in 67 healthy volunteers with normal body weight. We also quantified the levels of protein C and prothrombin fragment 1+2. Obese patients showed significantly higher levels of activated protein C, protein C and fragment 1+2. No correlation was found between activated protein C and fragment 1+2 levels in obese patients. After three months of diet, a significant decrease in activated protein C and fragment 1+2 was observed. In conclusion, activated protein C levels are increased in obese patients, but only a minor fraction of this increase may be explained by the higher thrombin generation and C protein levels. Activated protein C levels decrease with weight loss, due in part to a thrombin generation reduction.

Erythrocyte membrane composition in patients with primary hypercholesterolemia

There are conflicting results regarding the erythrocyte membrane cholesterol and phospholipid content in patients with primary hypercholesterolemia (PHC), due to methodological problems in obtaining haemoglobin-free ghosts. At the same time, the different units used and the fact that the cholesterol and phospholipids are not expressed in relation with integral protein membrane content, produces contradictory results. We have analysed in 33 patients with PHC (12 male, 31 female) aged 43+/-12 years and in 33 healthy normolipaemic volunteers (9 male, 24 female) aged 43+/-13 years plasma lipids, along with, erythrocyte membrane cholesterol, phospholipids and integral proteins. PHC patients showed increased erythrocyte membrane cholesterol: 0.36+/-0.15 mg/mg when compared with controls: 0.29+/-0.75 mg/mg; p=0.018. Phospholipid membrane content, although higher in the cases, did not reach statistical significance (PHC patients: 0.38+/-0.15 mg/mg vs. 0.33+/-0.72 mg/mg; p=0.098). The cholesterol/phospholipids ratio (Chol/Ph) was 0.99+/-0.22 in PHC patients versus 0.92+/-0.28 in controls; p=0.127. Our results suggest that there is a slight increase in erythrocyte membrane cholesterol in patients with PHC. Given the increasing importance of erythrocyte membrane cholesterol in the stability of the atheroma plaque due its possible contribution to the clinical signs of ischaemic heart disease, it seems relevant to determine this parameter in risk populations. Therefore, a simple and reproducible method needs to be standardised which would enable comparisons between laboratories and facilitate further studies aimed to it as a marker of acute coronary syndromes.

Erythrocyte hyperaggregation in obesity: determining factors and weight loss influence

OBJECTIVE

To compare erythrocyte aggregation (EA) in patients with severe obesity without other cardiovascular risk factors with a control group, using the Myrenne and the Sefam aggregometers, and to evaluate the effect of weight loss on this parameter.

RESEARCH METHODS AND PROCEDURES

This was a longitudinal, clinical intervention study of a very low-calorie diet for 4 weeks followed by a low-calorie diet for 2 months. In 67 severely obese patients, an anthropometric and analytical evaluation [plasmatic lipids, fibrinogen (Fbg), and EA] was performed at baseline and 3 months after diet. The same determinations were performed in 67 normal-weight volunteers. EA was measured with the Myrenne MA1, which determines EA at stasis (EA0) and at a low shear of 3 seconds(-1) (EA1), and the Sefam aggregometer, which determines aggregation index at 10 seconds(-1) (IA10), aggregation time (Ta), and disaggregation threshold (gammaD). Insulin resistance (IR) was calculated by homeostasis model assessment.

RESULTS

Obese patients showed higher Fbg levels, EA0, EA1, IA10, and gammaD values, and lower Ta values. Differences between obese patients and control group for EA0, EA1, Ta, IA10, and gammaD disappeared after adjusting for BMI or for homeostasis model assessment but were maintained after adjusting for Fbg or low-density lipoprotein-cholesterol. Obese patients with IR showed higher EA0 and EA1 values. After weight loss, EA1 showed a significant improvement.

DISCUSSION

Obese patients show increased EA. Erythrocyte hyperaggregation does not seem to be related to a high Fbg level or to an abnormal lipid profile but to IR. Hyperagreggation improves after weight loss.

Fibrinogen, plasma viscosity and blood viscosity in obesity. Relationship with insulin resistance

Plasma viscosity (PV) and blood viscosity (BV) have been scarcely evaluated in morbid obese patients with no other concomitant cardiovascular risk factors. Contradictory results have been published regarding the influence of insulin resistance on these rheological parameters in obesity. In 67 severe or morbid obese patients without other cardiovascular risk factors (51 women and 11 men, aged 34+/-11 years), fibrinogen, PV and BV at native (nBV) and corrected 45% hematocrit (cBV) have been determined, and insulin resistance has been calculated with homeostasis model assessment (HOMA) index, in basal conditions and after a three month diet period. The same determinations were performed in 67 healthy volunteers (45 women, 22 men, aged 32+/-10 years) at baseline and three months later. When cases and controls were compared, obese patients showed higher fibrinogen levels (P<0.001), PV (P=0.050) and cBV (P=0.035), and showed a higher insulin resistance than the control group (P<0.001). Differences in PV were maintained after adjusting for BMI (P=0.001), but disappeared after adjusting for HOMA (P=0.391) fibrinogen (P=0.367) and LDL-chol (P=0.097). Differences between obese patients and the control group for cBV disappeared after adjusting for BMI (P=0.739), HOMA (P=0.744), fibrinogen (P=0.907), LDL-chol (P=0.283) and PV (P=0.112). The achieved weight loss (8.7+/-3.53%) was not accompanied by any changes in these rheological parameters (P>0.050). Obese patients show increased fibrinogen levels, PV and cBV. These rheological disturbances seem to be associated with insulin resistance and the metabolic syndrome, and do not seem to improve with moderate weight loss.

Erythrocyte deformability in obesity measured by ektacytometric techniques

Erythrocyte deformability (ED) has been scarcely evaluated in obese patients without other concomitant cardiovascular risk factors and contradictory results have been published regarding the influence of plasma lipids on the erythrocyte membrane lipid composition and insulin resistance on this rheological parameter. In 67 severe or morbid obese patients without other cardiovascular risk factors (51 women and 11 men, aged 34+/-11 years) and in 67 controls (45 women and 22 men, aged 32+/-10 years), ED has been determined by ektacytometric techniques in a Rheodyn SSD, the elongation index (EI) being measured at 12, 30 and 60 Pa, along with plasma lipids, red blood cell membrane lipids (cholesterol and phospholipids) and insulin resistance indexes in basal conditions and after a three month diet period. No significant differences were obtained in the EI between obese patients and the control group at any of the shear stresses tested (P>0.05). The cholesterol and phospholipid content of the red blood cell membrane did not significantly differ between cases and controls (P>0.05). Obese patients with metabolic syndrome showed lower EI at 30 and 60 Pa than those without metabolic syndrome (P=0.014 and P=0.031 respectively). Weight loss was not accompanied by any changes in these rheological parameters. Obesity itself does not seem to modify ED. However, metabolic syndrome seems to decrease ED, possibly through insulin resistance.

Management of diabetic ketoacidosis in a teaching hospital

The aim of our study was to evaluate clinical management of diabetic ketoacidosis (DKA) in a teaching hospital. We followed all the patients hospitalised for DKA over six years (1995-2000), and we recorded clinical data, laboratory finding at entrance and clinical management. We compared the data to the standards set in guidelines. Our study showed an important delay of initiation of intravenous fluid (70% of cases), an under-replacement with intravenous fluid (69% of cases) and with potassium therapy (80% of cases), and an excessive use of alkali therapy. In conclusion, suboptimal management of DKA occurred in a large percentage of patients.

Rheological profile in severe and morbid obesity. Preliminary results

The association of hemorheological alterations with morbid obesity remains a question of debate. In order to ascertain whether morbid obese subjects show certain hemorheological alterations which might be involved in the higher thrombotic risk which characterizes these subjects, we determine glucose, plasma lipids, apolipoproteins, fibrinogen, hematocrit, blood viscosity (Brookfield DVIII viscosimeter), both at native and corrected hematocrit of 45%, plasma viscosity (Fresenius capillary viscosimeter), erythrocyte aggregation (Myrenne aggregometer), both at stasis and at 3 s(-1) at 45% hematocrit and erythrocyte indexes in 41 morbid obese subjects (32 female, 9 male aged 33+/-10 years), and in a well matched non-obese control group (40 female, 15 male, aged 32+/-10 years). Mean BMI in the morbid obese group was 44.9+/-6.7 kg/m2 vs 23.5+/-4.8 kg/m2 in the control group (p<0.001). Morbid obese subjects when compared with the control group showed a statistically higher glucose level (p<0.001), LDL-cholesterol (p=0.019), triglycerides (p<0.001), apoB (p=0.019), apoB/A1 (p<0.001), fibrinogen (p<0.001), erythrocyte aggregation (p<0.001), and a statistically lower HDL-cholesterol (p<0.001). No differences between both groups were observed regarding total-cholesterol, plasma viscosity, blood viscosity and hematocrit (p=0.109; p=0.690; p=0.510; p=0.950), respectively. After the adjustment for BMI, differences in glucose, LDL-cholesterol, triglycerides, apoB, apoB/A1, and erythrocyte aggregation did not reach the statistical significance, and differences in fibrinogen were borderline significant (p=0.051), showing a direct effect of BMI on the detected differences between obese and non-obese. Our results suggest that in morbid obese subjects the increased fibrinogen levels and the altered lipid profile associated with their higher BMI, could in addition to its known mechanisms on haemostasis, favour both venous and arterial thrombotic events by enhancing erythrocyte aggregation.

Effect of a hypocaloric diet on lipids and rheological profile in subjects with severe and morbid obesity. A follow-up study

Discrepant results have been published regarding modifications of rheological parameters in obese subjects after a low caloric diet (LCD). In order to ascertain whether a decrease in BMI associated to a LCD, is accompanied by changes in the hemorheological parameters, we determined in 41 morbid obese subjects (32 female, 9 male aged 33+/-10 years) BMI, glucose, plasmatic lipids and apolipoproteins, fibrinogen, blood viscosity (Brookfield viscosimeter), plasma viscosity (Fresenius capillary viscosimeter), erythrocyte aggregation (Myrenne aggregometer), hematocrit and erythrocyte indexes, before starting on a LCD and 1 and 3 months after. During the first month obese subjects received a very low caloric diet (VLCD) (Modifast) providing 458 kcal per day. The second and third month they received a LCD providing 1500 kcal/day for men and 1200 kcal/day for women. One month after starting on a VLCD, a statistical significant decrease in glucose (p<0.001), Total-cholesterol (p<0.001), LDL-cholesterol (p<0.001), triglycerides (p=0.012), apoB (p<0.001) and erythrocyte aggregation (p<0.001) were observed together with a concomitant decrease in BMI (p<0.001). The expected decrease in HDL-cholesterol associated with a low fat diet was also noted in these individuals. No changes in fibrinogen, hematocrit, blood viscosity or plasma viscosity were observed. At 3 months only a slight increase in BMI was observed regarding the one month period, glucose being the only parameter which remained statistically lower. All the other significant parameters returned to their basal values at 3 months. VLCD (Modifast) is associated to a significant decrease in BMI with the corresponding improvement in glucose, lipids and erythrocyte aggregation at one month. However a LCD alone does not produce a further decrease in weight and both lipids and erythrocyte aggregation return to the basal situation at three months.

Influence of plasmatic lipids on the hemorheological profile in healthy adults

Some hemorheological parameters constitute risk factors for ischemic cardiovascular events. Most of these hemorheological factors are determined by the erythrocyte intrinsic properties and the high molecular weight plasmatic proteins, especially fibrinogen. The contribution of the plasmatic lipids to hemorheological factors is not well established. With this aim we determined hemorheological parameters in 112 healthy volunteers (62 males, 50 females) aged 35+/-10 years, range 19-54 years, members of our hospital staff. A complete set of rheological test was performed. Blood viscosity (BV) 230 sec(-1), plasma viscosity (PV), erythrocyte aggregation index (EAI), erythrocyte elongation index (EEI), hematocrit and fibrinogen. We also determined plasmatic lipids including total cholesterol (T-Ch) and its fractions (HDL-Ch, LDL-Ch, VLDL-Ch), triglycerides, lipoproteins (Apo B, Apo A(1), B/A(1)). Exclusion criteria were concomitant cardiovascular risk factors or any other associated pathology. Our results show a positive correlation between BV 230 sec(-1) and triglycerides (r=0.335) and negative with HDL-Ch (r=-0.451) (p=0.01), respectively; PV shows a positive correlation with T-Ch (r=0.297), LDL-Ch (r=0.298) and Apo B/A (r=0.290) (p=0.01). The EEI was negatively correlated with TG (p=0.05). Of all the rheological parameters evaluated, EAI is the factor which shows the highest significant correlation with plasmatic lipids: T-Ch (r=0.515), TG (r=0.303), LDL-Ch (r=0.507) and Apo B/A ratio (r=0.403); (p=0.01). These results suggest that plasmatic lipids contribute to modulate the blood rheological properties, slowing blood flow, favouring the development of atherothrombotics events, especially in stenotic areas or bifurcations in the vascular tree.

Rapid onset of Wernicke's encephalopathy following gastric restrictive surgery

A patient with severe vomiting following gastric banding developed Wernicke's encephalopathy. All neurological disorders disappeared with thiamine treatment. This complication may be prevented by keen awareness, early diagnosis and treatment, in patients with persistent vomiting. Vitamin and mineral supplementation must be taken in patients following bariatric surgery.

Association between diabetic ketoacidosis and thyrotoxicosis

Three cases of diabetic ketoacidosis precipitated by thyrotoxicosis are presented. Two of them are young women with type 1 diabetes mellitus; the third case is a middle-aged woman with type 2 diabetes mellitus. All of them were diagnosed with Graves' disease. They typically showed tachycardia at rest in spite of correction of the metabolic disorder. Hyperthyroidism worsens glycemic control in diabetic patients and may precipitate diabetic ketoacidosis. On the other hand, women with diabetes have a higher prevalence of Graves' disease. Thus, in diabetic ketoacidosis without an obvious triggering factor, the presence of hyperthyroidism should be investigated, particularly in women.

Massive triiodothyronine intoxication: efficacy of hemoperfusion?

A case of massive accidental triiodothyronine intoxication (1000-fold the usual therapeutic dose, for 8 days) is reported with important disturbances of cardiovascular and central nervous systems that required intensive care support. Serum free triiodothyronine levels were 4789 pmol L(-1) on admittance (normal values, 3.5-6.5 pmol x L(-1)). In the absence of a specific treatment, hemoperfusions were performed but failed to accelerate significantly the decay of blood levels of free triiodothyronine (apparent half-life 25.9 hours; 95% confidence interval: 19.8-37.4 hours). The patient, a young woman, made a satisfactory recovery, in spite of important clinical complications.