Mortality, Health Care Burden, and Treatment of CKD: A Multinational, Observational Study (OPTIMISE-CKD)

Key Points

Newly detected, moderately progressed CKD is associated with high clinical risks and health care costs. Most patients with moderately progressed CKD do not have diabetes and are at the same clinical risk as those with diabetes. Substantial inertia with kidney-protective treatment is observed when moderately progressed CKD is detected.

Background

Kidney-protective treatments (renin–angiotensin system inhibitors and sodium–glucose cotransporter-2 inhibitors [SGLT-2is]) can delay CKD progression, cardiovascular events, and death.

Methods

This observational cohort study used electronic health records and claims data from Japan, Sweden, and the United States to assess 1-year mortality/hospitalization event rates per 100 patient-years (PYs), cumulative hospital health care costs per patient, and kidney-protective treatment use before/after SGLT-2i (dapagliflozin) approval for CKD (2021) for patients with CKD stage 3–4 with/without type 2 diabetes (T2D).

Results

Among 449,232 patients (across-country median age range 74–81 years), 79% did not have T2D. Prevalence ranges for atherosclerotic cardiovascular disease and heart failure were 20%–36% and 17%–31%, respectively. Baseline kidney-protective treatment (renin–angiotensin system inhibitor and/or SGLT-2i) use was limited, especially among patients without T2D. Event rates were high for CKD (11.4–44.4/100 PYs) and heart failure (7.4–22.3/100 PYs). Up to 14.6% of patients had died within 1 year. Hospital costs were higher for CKD and heart failure than for atherosclerotic cardiovascular disease. After incident CKD, kidney-protective treatment initiation was low (8%–20%) and discontinuation was high (16%–27%), especially among patients without T2D.

Conclusions

Incident CKD was associated with substantial morbidity, mortality, costs, and undertreatment, especially in patients without T2D, who represented the majority of patients. This highlights an urgent need for early CKD detection and better kidney-protective treatment use in moderate CKD.

Heart failure outcomes by left ventricular ejection fraction in a contemporary region-wide patient cohort

AIMS

This study aimed to characterize a contemporary population with subtypes of incident or prevalent heart failure (HF) based on reduced (HFrEF), mildly reduced, or preserved (HFpEF) left ventricular ejection fraction (LVEF) and to assess how outcomes, healthcare, treatments, and healthcare costs vary between each subtype of incident HF.

METHODS AND RESULTS

Using Swedish data from the CardioRenal and Metabolic disease Heart Failure (CaReMe HF) study, updated to cover a more recent time period, this population-based study characterized patients from Stockholm County, Sweden, with incident HF (patients with a first HF diagnosis between 1 January 2015 and 31 December 2019) or prevalent HF (patients with a first HF diagnosis before 1 January 2020). Patients with incident HF had LVEF measured by echocardiography within ±90 days of their first HF diagnosis, and patients with prevalent HF within 5 years prior to the index date. The 13 375 patients with prevalent HF (39.2% women, mean age 73.9 years) had multiple comorbidities (cardiovascular diseases, chronic kidney disease, diabetes, and cancer). These were already highly prevalent at the time of the first HF diagnosis in the 8042 patients with incident HF (40.5% women, mean age 72.3 years). Patients with incident HFpEF received less specialist HF care at outpatient secondary care facilities following their first HF diagnosis than those with incident HFrEF. Patients with HFrEF had higher risks of complications and exerted a higher burden, in terms of care for and costs of HF, on the healthcare system.

CONCLUSIONS

This study of contemporary patients with incident HF demonstrates that those with HFpEF and HFrEF differ considerably in terms of clinical presentation, prognosis, and care, highlighting a potential to improve HF outcomes.

Subcutaneous adipose tissue dopamine D2 receptor is increased in prediabetes and T2D

PURPOSE

To evaluate the dopaminergic signaling in human adipose tissue in the context of obesity and type 2 diabetes (T2D) and potential direct implications in adipose tissue metabolism.

METHODS

mRNA and protein expression of dopamine receptors D1 and D2 (DRD1 and DRD2) were determined in subcutaneous adipose tissue from subjects without or with T2D and with different body weight, and correlated with markers of obesity, hyperglycemia, and insulin resistance. Glucose uptake and lipolysis were measured in adipocytes ex vivo following short-term exposure to dopamine, DRD1 receptor agonist (SKF81297), or DRD2 receptor agonist (bromocriptine).

RESULTS

DRD1 and DRD2 gene expression in subcutaneous adipose tissue correlated positively with clinical markers of insulin resistance (e.g. HOMA-IR, insulin, and triglycerides) and central obesity in subjects without T2D. Protein expression of DRD2 in subcutaneous adipose tissue, but not DRD1, is higher in subjects with impaired fasting glucose and T2D and correlated positively with hyperglycemia, HbA1c, and glucose AUC, independent of obesity status. DRD1 and DRD2 proteins were mainly expressed in adipocytes, compared to stromal vascular cells. Dopamine and dopaminergic agonists did not affect adipocyte glucose uptake ex vivo, but DRD1 and DRD2 agonist treatment inhibited isoproterenol-stimulated lipolysis.

CONCLUSION

The results suggest that protein expression of DRD2 in subcutaneous adipose tissue is up-regulated with hyperglycemia and T2D. Whether DRD2 protein levels contribute to T2D development or occur as a secondary compensatory mechanism needs further investigation. Additionally, dopamine receptor agonists inhibit adipocyte beta-adrenergic stimulation of lipolysis, which might contribute to the beneficial effects in lipid metabolism as observed in patients taking bromocriptine.

A retrospective nationwide analysis of evolocumab use in Sweden and its effect on low-density lipoprotein cholesterol levels

Background

Treatment with proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduces low-density lipoprotein cholesterol (LDL-C) levels and decreases the incidence of major ischaemic events in clinical trials. However, less is known about the efficacy of PCSK9 inhibition in clinical practice. This study aimed to describe the change in LDL-C levels over time and LDL-C goal achievement in patients with/without atherosclerotic cardiovascular disease (ASCVD), who were prescribed evolocumab in clinical practice, and to describe adherence to and persistence with treatment.

Methods

Patients in Sweden with at least one evolocumab prescription filled between July 2015 and May 2020 were included. Medical history and lipid-lowering therapy (LLT) were sourced from national registries. LDL-C levels before and after treatment initiation were assessed using medical records. Persistence with and adherence to evolocumab and oral LLT were assessed up to 12 months after treatment initiation using the refill-gap method and proportion of days covered, respectively.

Results

Of the 2,360 patients with at least one prescription for evolocumab, 2,341 were included; 1,858 had ASCVD. Persistence with (76%) and adherence to (86%) evolocumab were high throughout the 12 months following initiation. Mean LDL-C levels decreased by 53% (95% confidence interval [CI]: 51-55%) in patients adherent to evolocumab (n = 567) and 59% (95% CI: 55-63%) in patients adherent to evolocumab and oral LLT (n = 186). Similar reductions in LDL-C were observed in patients with/without ASCVD. Reduced LDL-C levels remained stable during follow-up. Amongst patients adherent to evolocumab and those adherent to evolocumab and oral LLT, 23 and 55% achieved the LDL-C goal of <1.4 mmol/L, respectively.

Conclusions

The evolocumab LDL-C-lowering effect observed in clinical trials was confirmed in clinical practice in Sweden, particularly in patients also treated with oral LLT. During follow-up, adherence to and persistence with evolocumab were high, with stable reduced levels of LDL-C during observation.

Hyperkalaemia-related reduction of RAASi treatment associates with more subsequent inpatient care

BACKGROUND

Hyperkalaemia is a barrier to achieving optimal, guideline-directed treatment with renin-angiotensin-aldosterone system inhibitors (RAASi) in patients with chronic kidney disease (CKD) and/or heart failure (HF). This study describes the association between hyperkalaemia-related RAASi treatment reduction and number of hospitalized days in patients with CKD and/or HF in Sweden and Japan.

METHODS

Using data from health registers and hospital medical records, patients with CKD and/or HF currently receiving RAASi who experienced an index hyperkalaemia episode were identified and categorized as having maintained or reduced RAASi treatment post-index; propensity-score matching (1:1) was applied to balance the groups in terms of baseline characteristics. Changes in the number of all-cause, CKD-, and HF-related hospitalized days per patient-year during 6 months before versus after index, and the number of days alive and out of hospital (DAOH) during 6 months post-index were described.

RESULTS

Overall, 20 824 and 7789 patients were included from Sweden and Japan, respectively, 42% and 38% of whom reduced their RAASi treatment after the index hyperkalaemia episode. During the 6 months post-index, all-cause hospitalization (95% confidence intervals) increased by 18.2 (17.0-19.2) days per person-year in Sweden and 17.9 (17.4-18.5) days per person-year in Japan among patients with reduced RAASi treatment compared with increases of 9.4 (8.6-10.4) and 8.5 (8.0-9.0) days per person-year, respectively, among patients with maintained RAASi treatment. Mean (standard deviation) DAOH were 121.5 (75.0) in Sweden and 141.7 (54.5) in Japan among patients with reduced RAASi treatment compared with 154.0 (51.3) and 157.5 (31.6) days, respectively, among patients with maintained RAASi treatment.

CONCLUSION

Patients whose RAASi treatment was reduced after a hyperkalaemia episode had more hospitalized days and fewer DAOH compared with patients whose RAASi treatment was maintained.

Health care registers can be instrumental for endpoint capture in clinical diabetes trials: example of microvascular complications in Swedish patients with type 2 diabetes

AIMS

SMARTEST is a register-based randomized clinical trial (RRCT) that compares dapagliflozin to metformin in early-stage type 2 diabetes. The primary outcome includes progression of microvascular complications based on data from the Swedish National Diabetes Register (NDR). In this sub-study, the aim was to validate microvascular complication variables in the NDR against electronic health records (EHRs).

METHODS

Data were extracted from EHRs of 276 SMARTEST participants with a median observation period of 3 years in the Uppsala, Örebro and Sörmland counties and compared with NDR data. Agreement was determined for all corresponding data entries as well as for progression of microvascular complications after randomization.

RESULTS

The agreement for all corresponding data entries was 98.9% (Intraclass Correlation Coefficient 0.999) for creatinine and eGFR, 95.1% for albuminuria, 91.6% for foot-at-risk and 98.2% for retinopathy status (Kappa 0.67-0.91). The agreement for progression of microvascular complications was 98.0% for CKD stage, 98.9% for albuminuria grade, 96.3% for foot-at-risk grade and 99.6% for retinopathy grade progression (Gwet's AC₁ 0.96-1.00).

CONCLUSION

Microvascular complication variables in the NDR show good agreement with EHR data. The use of a well-established national health care registry, exemplified by the NDR, for endpoint collection in RRCTs such as SMARTEST is supported by this study.

Low-density lipoprotein cholesterol reduction with evolocumab and its use in clinical practice: evidence from Swedish national register data

Background/Introduction

Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors reduce low density lipoprotein cholesterol (LDL-C) levels by around 50% to 60%, and the risk of cardiovascular events in patients with atherosclerotic cardiovascular disease (ASCVD) in randomized clinical trials. Data on LDL-C reduction with PCSK9 inhibitors and its use in clinical practice is lacking.

Purpose

Assess LDL-C reduction with the PCSK9 inhibitor evolocumab and its use in clinical practice in Sweden.

Methods

Population-based, retrospective, longitudinal, observational study of patients initiating evolocumab treatment between July 2015 and May 2020. Patients undergoing lipoprotein apheresis were excluded. Patient level data was obtained from national diagnosis and pharmaceutical registers (covering 100% of the Swedish population), and electronic health records (covering 60% of the Swedish population). The use of evolocumab was assessed based on persistence with and adherence to treatment. Patients were defined as being persistent if they were still taking evolocumab 12 months after treatment initiation. Medication gaps were allowed until a last gap of ≥56 days. Patients were defined as being adherent if the proportion of days covered (PDC) by the drug was ≥80% during that same period. Mean LDL-C reduction was estimated 3 months after evolocumab treatment initiation, using a Generalized Least Squares regression model.

Results

Overall, 2341 patients were included in the analysis, with a median follow-up of 376 days. Median age was 65 years, 43% were women, 79% had a history of ASCVD and, among them, 94% had had a coronary event and 24% had diabetes. 44% of the patients had LDL-C available. Median LDL-C was 4.1 mmol/L and 64% of the patients were receiving oral lipid-lowering treatment (LLT). After 12 months of treatment, 76% of the patients were persistent with evolocumab. In these patients, median PDC over 12 months was 93%, with 86% of these patients being adherent (PDC ≥80%). In the overall population (n=724), the estimated mean LDL-C reduction with evolocumab at 3 months was 48% (2.1 mmol/L, from 4.4 mmol/L at baseline). In patients who were adherent to evolocumab during the first 6 months (n=567), LDL-C reduction was 53% (2.2 mmol/L, from 4.3 mmol/L at baseline) (see figure). In patients who were adherent to both evolocumab and oral LLT (PDC ≥80% over a period of 3 months before and after evolocumab initiation) (n=186), LDL-C reduction was 59% (2.1 mmol/L, from 3.6 mmol/L at baseline). The estimated mean LDL-C reduction remained stable over a 6-month period.

Conclusions

Persistence with and adherence to evolocumab treatment were high over 12 months. LDL-C reduction with evolocumab in clinical practice was similar to that observed in randomized clinical trials and remained stable over 6 months. At evolocumab treatment initiation, many patients had high LDL-C levels and underused oral LLT, potentially due to statin intolerance.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen

Role of Estrogen and Its Receptors in Adipose Tissue Glucose Metabolism in Pre- and Postmenopausal Women

CONTEXT

Reduced estrogen levels in postmenopausal women predispose them to metabolic side effects, including insulin resistance and type 2 diabetes; however, the cellular mechanisms are not well understood.

OBJECTIVE

This work aimed to study the expression of estrogen receptors in adipose tissue from pre- and postmenopausal women and the effects of estradiol (E2) on glucose uptake of adipocytes.

METHODS

Subcutaneous (SAT) and visceral adipose tissue (VAT) obtained from pre- and postmenopausal women (19-51 and 46-75 years old, respectively) were used to measure gene expression of ESR1 and ESR2. SAT tissue was incubated with E2, and glucose uptake and estrogen receptor levels were measured. Polymorphisms in ESR1 and ESR2 were addressed in public databases to identify single nucleotide polymorphisms associated with metabolic traits.

RESULTS

ESR2 expression was lower in pre- vs postmenopausal women, corresponding to lower ESR1:ESR2 gene expression ratio in postmenopausal women. In premenopausal women, the expression of ESR1 was higher in VAT than in SAT. In both pre- and postmenopausal women, ESR2 expression was lower in VAT than in SAT. In late, but not pre- or early postmenopausal women, E2 reduced glucose uptake and GLUT4 protein and increased expression of ESR2. ESR1 polymorphisms were associated with weight, body fat distribution, and total cholesterol, and ESR2 polymorphisms were associated with total cholesterol and triglyceride levels and with body fat percentage.

CONCLUSION

E2 inhibits glucose utilization in human adipocytes in late postmenopausal women. Changes in glucose utilization over time since menopause may be explained by a lower ESR1:ESR2 ratio. This can have clinical implications on the timing of estrogen treatment in postmenopausal women.

Real-World Effectiveness of Anti-Resorptive Treatment in Patients With Incident Fragility Fractures-The STORM Cohort-A Swedish Retrospective Observational Study

Results from real-world evidence (RWE) from the largest healthcare region in Sweden show low uptake of antiresorptive (AR) treatment, but beneficial effect in those receiving treatment, especially for the composite outcome of hip fracture or death. For RWE studies, Sweden is unique, with virtually complete coverage of electronic medical records (EMRs) and both regional and national registries, in a universal publicly funded healthcare system. To our knowledge, there is no previous RWE study evaluating the efficacy of AR treatment compared to no AR treatment after fragility fracture, including data on parenteral treatments administered in hospital settings. The Stockholm Real World Management (STORM) study cohort was established in the healthcare region of Stockholm to retrospectively assess the effectiveness of AR treatment after first fragility fracture using the regional EMR system for both hospital and primary care. Between 2012 and 2018, we identified 69,577 fragility fracture episodes among 59,078 patients, men and women, 50 years and older. Of those, 21,141 patients met inclusion and exclusion criteria (eligible cohort). From these, the final matched study cohort comprised 9840 fragility fractures (cases receiving AR treatment [n = 1640] and controls not receiving AR treatment [n = 8200]). Propensity scores were estimated using logistic regression models with AR treatment as outcome and confounders as independent variables followed by analysis using Cox proportional hazard models. Real world evidence from Sweden's largest healthcare region, comprising a quarter of the Swedish population, show that only 10% of patients receive AR treatment within 1 year after a fragility fracture. Factors associated with not receiving treatment include having a diagnosis of cardiovascular disease. In those treated, AR have positive effects particularly on the composite of fracture and death (any fracture/death and hip fracture/death) in individuals matched for all major confounders. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).

CDKN2C expression in adipose tissue is reduced in type II diabetes and central obesity: impact on adipocyte differentiation and lipid storage?

CDKN2C/p18 (Cyclin-Dependent Kinase Inhibitor 2C) is a cell growth regulator that controls cell cycle progression and has previously been associated with increased risk for type II diabetes (T2D) and reduced peripheral adipose tissue (AT) storage capacity. This study explored the role of CDKN2C in AT lipid and glucose metabolism in T2D. Expression of CDKN2C and other genes was analyzed by transcriptomics, or real-time PCR in subcutaneous AT (SAT) samples obtained from T2D and control subjects matched for sex, age and BMI and also in paired SAT and omental AT (OAT) samples. Functional studies included adipocyte glucose uptake and lipolysis rates. CRISPR/Cas9 CDKN2C gene knockdown was performed in human preadipocytes to assess adipogenesis. CDKN2C mRNA expression in SAT and OAT was reduced in T2D and obese subjects compared to controls. CDKN2C expression in SAT was inversely correlated with measures of hyperglycemia, insulin resistance and visceral adiposity and positively correlated with expression of genes in several metabolic pathways, including insulin signaling and fatty acid and carbohydrate metabolism. CDKN2C protein was mainly expressed in adipocytes compared to stromal vascular cells, and its gene and protein expression was up-regulated during adipocyte differentiation. Knockdown of CDKN2C did not affect the percentage of differentiating cells compared to wild type cultures. However, CDKN2C knockdown cultures had significantly lower expression of differentiation markers CEBPA, ADIPOQ and FASN and transiently reduced lipid accumulation per adipocyte during differentiation. Our findings suggest that adipose CDKN2C expression might be reduced as a consequence of insulin resistance and obesity, and this can further contribute to impairment of SAT lipid storage.

Effects of lipid-lowering treatment intensity and adherence on cardiovascular outcomes in patients with a recent myocardial infarction: a Swedish register-based study

BACKGROUND

Oral lipid-lowering treatment (LLT) is the standard of care for patients with cardiovascular disease (CVD). However, insufficient treatment intensity and poor adherence can lead to suboptimal treatment benefit, rendering patients at increased risk of CVD.

AIMS

The objective of this study was to evaluate trends in LLT intensity and adherence in Sweden over time, and their association with major adverse cardiovascular events (MACE) after recent myocardial infarction (MI), and also to assess the impact of transition from secondary to primary care on intensity and adherence.

METHODS AND RESULTS

This retrospective observational cohort study used data from Swedish nationwide patient registers and included patients on LLT after an MI in the years 2010-2016 (n = 50,298; mean age, 68 years; 69% men). LLT intensity was evaluated over time (overall, for 2010-2013 and for 2014-2016) as the proportion of patients prescribed low-, moderate-, and high-intensity LLT. Adherence was assessed as the proportion of days covered. A combined measure of intensity and adherence was also considered. Differences in treatment patterns and MACE were assessed. Initiation of high-intensity LLT increased over the two time periods studied (2010-2013, 32%; 2014-2016, 91%). Adherence varied by LLT intensity and was highest in patients receiving high-intensity LLT (>80%), especially during the first time period. Little change in treatment intensity or the combined measure of intensity and adherence was observed after transition to primary care. There was a significant association between the combined measure of intensity and adherence and MACE reduction (hazard ratio [95% confidence interval] per 10% increase in the combined measure: 0.84 [0.82-0.86]; P < 0.01).

CONCLUSION

The proportion of post-MI patients with high LLT intensity and adherence has increased in recent years, with little change after transfer from specialist to primary care. The combination of LLT intensity and adherence is important for preventing future cardiovascular events.

A third dose SARS‑CoV‑2 BNT162b2 mRNA vaccine results in improved immune response in hemodialysis patients

BACKGROUND

The hemodialysis (HD) population has been a vulnerable group during the coronavirus disease 2019 (COVID-19) pandemic. Advanced chronic kidney disease with uremia is associated with weaker immune response to infections and an attenuated response to vaccines. The aim of this study was to study the humoral and cellular response to the second and third doses of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS‑CoV‑2) BNT162b2 mRNA vaccine in HD patients and to follow the response over time.

METHODS

The patients received their first two vaccine doses from 28 December 2020 within a 4-week interval and the third dose in September 2021 and were followed-up for humoral and cellular immune response at 1) 7-15 weeks and 2) 6-8 months after dose two (no t-cell reactivity measured), and 3) 3 weeks and 4) 3 months after dose three. Fifty patients were initially enrolled, and 40 patients were followed during the entire study. Levels of COVID-19 (SARS-CoV-2) IgG antibody against the Spike antigen (anti-S) and T-cell reactivity testing against the Spike protein using Enzyme-Linked ImmunoSpot (ELISPOT) technology were evaluated.

RESULTS

IgG antibodies to anti-S were detected in 35 (88%) of the 40 patients 7-15 weeks after vaccine dose two, 31 (78%) were positive, and 4 (10%) borderline. The median anti-S titer was 606 Abbott Units/milliliter (AU/mL) (interquartile range [IQR] 134-1,712). Three months after the third dose, anti-S was detected in 38 (95%) of 40 patients (P < 0.01 compared to after dose two), and the median anti-S titer was 9,910 AU/mL (IQR 2,325-26,975). Cellular reactivity was detected in 22 (55%), 34 (85%), and 28 (71%) of the 40 patients, and the median T-cell response was 9.5 (IQR 3.5-80), 51.5 (14.8-132), and 19.5 (8.8-54.2) units, respectively, for 6-8 months after dose two, 3 weeks, and 3 months after dose three.

CONCLUSIONS

Our data show that a third dose of SARS‑CoV‑2 BNT162b2 mRNA vaccine gives a robust and improved immunological response in HD patients, but a few patients did not develop any anti-S response during the entire study, indicating the importance to monitor the vaccine response since those who do not respond could now be given monoclonal antibodies if they contract a COVID-19 infection or in the future antivirals.

Humoral and cellular response to SARS-CoV-2 BNT162b2 mRNA vaccine in hemodialysis patients

Background

Hemodialysis (HD) patients have an increased risk of acquiring infections due to many health care contacts and may, in addition, have a suboptimal response to vaccination and a high mortality from Covid-19 infection.

Methods

In 50 HD patients (mean age 69.4 years, 62% men) administration of SARS-CoV-2BNT162b2 mRNA vaccine began in Dec 2020 and the immune response was evaluated 7–15 weeks after the last dose. Levels of Covid-19 (SARS-CoV-2) IgG antibody against the nucleocapsid antigen (anti-N) and the Spike antigen (anti-S) and T-cell reactivity testing against the Spike protein using ELISPOT technology were evaluated.

Results

Out of 50 patients, anti-S IgG antibodies indicating a vaccine effect or previous Covid-19 infection, were detected in 37 (74%), 5 (10%) had a borderline response and 8 (16%) were negative after two doses of vaccine. T-cell responses were detected in 29 (58%). Of the 37 patients with anti-S antibodies, 25 (68%) had a measurable T-cell response. 2 (40%) out of 5 patients with borderline anti-S and 2 (25%) without anti-S had a concomitant T-cell response. Twenty-seven (54%) had both an antibody and T-cell response. IgG antibodies to anti-N indicating a previous Covid-19 disease were detected in 7 (14%) patients.

Conclusions

Most HD patients develop a B- and/or T-cell response after vaccination against Covid-19 but approx. 20% had a limited immunological response. T-cell reactivity against Covid-19 was only present in a few of the anti-S antibody negative patients.

A real-world analysis of characteristics and lipid-lowering therapy use in patients initiating treatment with evolocumab in Sweden

Background/Introduction

Proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitors reduce low-density lipoprotein cholesterol (LDL-C) levels and the risk of cardiovascular events in patients with atherosclerotic cardiovascular disease (ASCVD) in clinical trials. In January 2019, evolocumab reimbursement recommendation in Sweden was broadened to include patients on maximally tolerated oral lipid-lowering therapy (LLT) and either ASCVD and LDL-C ≥2.5 mmol/L, or familial hypercholesterolemia (FH) with no ASCVD and LDL-C ≥3.0 mmol/L.

Purpose

Describe characteristics and LLT use in patients initiating treatment with evolocumab in the context of the 2019 reimbursement recommendation in Sweden.

Methods

Cross-sectional, population-based, retrospective, observational study of patients initiating treatment with evolocumab between January 2019 and June 2020. Data were obtained from national healthcare registers and electronic medical records, covering more than half of the Swedish population.

Results

Out of 1560 patients included, 41% had LDL-C available ≤3 months prior to treatment initiation with evolocumab. Among those with LDL-C available, 79% had ASCVD and 19% had definite, probable or possible FH with no ASCVD. Mean pre-treatment LDL-C levels were 3.7 and 5.0 mmol/L for patients with ASCVD, and FH with no ASCVD, respectively. Most of the patients, 84.6% and 80.0%, respectively, had been ever treated with both statins and ezetimibe. However, 28.0% and 38.3% of them, respectively, were not on oral LLT at the time of treatment initiation with evolocumab. Patient characteristics and LLT use are presented in Table 1.

Conclusions

Patients initiating treatment with evolocumab in Sweden had pre-treatment LDL-C levels far from treatment targets, despite being at very high risk for cardiovascular events. Most of the patients had been treated with both statins and ezetimibe in the past. However, almost a third of them were not using oral LLT at the time of treatment initiation with evolocumab. The conditions in the 2019 evolocumab reimbursement recommendation in Sweden were generally met.

Funding Acknowledgement

Type of funding sources: Private company. Main funding source(s): Amgen

Cardiovascular Event Rates After Myocardial Infarction or Ischaemic Stroke in Patients with Additional Risk Factors: A Retrospective Population-Based Cohort Study

Introduction

The impact of additional risk factors on major cardiovascular event (MACE) rates in patients with a history of myocardial infarction (MI) or ischaemic stroke (IS) treated with statins is not well defined.

Methods

In this retrospective population-based cohort study, patients with a history of MI or IS treated with moderate- or high-intensity statins were identified using Swedish national register data. Patients were incident (index event between July 2006 and December 2014 and followed from diagnosis) or prevalent (MI or IS before July 2006 and followed thereafter). Four subgroups were defined on the basis of additional risk factors associated with increased cardiovascular risk: diabetes mellitus with target organ damage; chronic kidney disease stages 3–4; index event within 2 years after prior MI or IS; and polyvascular disease. First and total MACE rates (i.e. MI, IS, or cardiovascular death) were calculated, and first MACE 10-year risks (prevalent cohort only) were predicted.

Results

Numerically, MACE rates in subgroups were 1.5–3 times higher than in overall populations, and were highest in the 2 years after the index event. First MACE rates in the additional risk factor subgroups were 17.2–33.5 per 100 person-years for the incident cohorts and 9.9–13.2 per 100 person-years for the prevalent cohorts. Total MACE rates per 100 person-years were 20.1–39.8 per 100 person-years and 12.4–17.6 per 100 person-years, respectively.

Conclusion

Despite previous use of moderate- or high-intensity statins, patients with a history of MI or IS, and additional risk factors remain at very high cardiovascular risk.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-01852-1.

Statin dose titration patterns and subsequent major cardiovascular events in very high-risk patients: estimates from Swedish population-based registry data

AIMS

Clinical studies have demonstrated the efficacy of intensive statin therapy in lowering low-density lipoprotein cholesterol and cardiovascular (CV) events. Our objective was to examine statin titration patterns and the association between titration patterns and subsequent CV events in very high-risk patients.

METHODS AND RESULTS

Using Swedish national population-based registry data, we identified 192 435 patients with very high risk of atherosclerotic CV disease initiated on moderate-intensity statin therapy between 2006 and 2013. Outcomes of interest were titration to high-intensity therapy and the major adverse cardiovascular events (MACE) composite (myocardial infarction, ischaemic stroke, and CV death) outcome. Cumulative incidence of MACE was assessed by titration status 1-year post-treatment initiation in patients adherent to treatment during the first year, using a 12-week cut-off from initiation to define early, delayed and no up-titration to high-intensity statins. Cox regression analysis was used to estimate adjusted hazard ratios (HRs). In 144 498 eligible patients, early titration was associated with significantly lower risk of MACE in the subsequent 2 years compared to no up-titration (HR 0.76, P < 0.01]. Delayed up-titration was associated with a smaller reduction (HR 0.88, P = 0.08). The majority of patients did not up-titrate.

CONCLUSION

Early up-titration to high-intensity statins was independently associated with lower risk of subsequent CV events compared to no up-titration. Delayed up-titration was not associated with the same benefit. Despite the higher risk associated with no up-titration, few patients at very high CV risk who started treatment on moderate-intensity up-titrated to high intensity, indicating a potential need for more aggressive lipid management of these patients in clinical practice.

Burden of Treatment-Induced Peripheral Neuropathy in Patients with Multiple Myeloma in Sweden

INTRODUCTION

Treatment-induced peripheral neuropathy (TIPN) is a complication of multiple myeloma (MM) treatment.

OBJECTIVE

This real-world, retrospective study used electronic medical record (EMR) data from 3 Swedish clinics to assess the occurrence and economic burden of TIPN in patients with MM.

METHODS

Eligible patients had an MM diagnosis in the Swedish Cancer Registry between 2006 and 2015 and initiated treatment during that period. Follow-up was until last EMR visit, death, or study end (April 2017). The current analyses included patients receiving bortezomib, lenalidomide, carfilzomib, or thalidomide at any treatment line. To discern healthcare resource utilization (HCRU) and costs associated with TIPN from other causes, patients with TIPN were matched with those without on baseline characteristics, treatment, and line of therapy. All analyses were descriptive.

RESULTS

Overall, 457 patients were included; 102 (22%) experienced TIPN. Patients experiencing TIPN during first-line treatment mostly received bortezomib-based regimens (n = 48/57 [84%]); those with TIPN during second- and third/fourth-line treatment mostly received lenalidomide/thalidomide-based regimens (19/31 [61%], 8/14 [57%], respectively). Patients with TIPN had higher HCRU/costs than those without TIPN (mean differences in hospital outpatient visits: 5.2, p = 0.0031; total costs per patient-year: EUR 17,183, p = 0.0007).

CONCLUSIONS

Effective MM treatments associated with a reduced incidence of TIPN could result in decreased healthcare expenditure.

3-Hydroxyisobutyrate, A Strong Marker of Insulin Resistance in Type 2 Diabetes and Obesity That Modulates White and Brown Adipocyte Metabolism

Circulating branched-chain amino acids (BCAAs) associate with insulin resistance and type 2 diabetes. 3-Hydroxyisobutyrate (3-HIB) is a catabolic intermediate of the BCAA valine. In this study, we show that in a cohort of 4,942 men and women, circulating 3-HIB is elevated according to levels of hyperglycemia and established type 2 diabetes. In complementary cohorts with measures of insulin resistance, we found positive correlates for circulating 3-HIB concentrations with HOMA2 of insulin resistance, as well as a transient increase in 3-HIB followed by a marked decrease after bariatric surgery and weight loss. During differentiation, both white and brown adipocytes upregulate BCAA utilization and release increasing amounts of 3-HIB. Knockdown of the 3-HIB-forming enzyme 3-hydroxyisobutyryl-CoA hydrolase decreases release of 3-HIB and lipid accumulation in both cell types. Conversely, addition of 3-HIB to white and brown adipocyte cultures increases fatty acid uptake and modulated insulin-stimulated glucose uptake in a time-dependent manner. Finally, 3-HIB treatment decreases mitochondrial oxygen consumption and generation of reactive oxygen species in white adipocytes, while increasing these measures in brown adipocytes. Our data establish 3-HIB as a novel adipocyte-derived regulator of adipocyte subtype-specific functions strongly linked to obesity, insulin resistance, and type 2 diabetes.

Cardiovascular event rates in a high atherosclerotic cardiovascular disease risk population: estimates from Swedish population-based register data

Aims

This study aimed to estimate the rate of cardiovascular (CV) events in the real world in patients at high risk of recurrent CV events similar to the FOURIER trial population.

Methods and results

A retrospective population-based cohort study was conducted using Swedish national registers from 1 July 2001 to 31 December 2015. Patients in the atherosclerotic cardiovascular disease (ASCVD) prevalent cohort met the FOURIER-like inclusion criteria, including treatment with high/moderate-intensity statins, on 1 July 2006. Additionally, two cohorts defined by diagnosis of incident ischaemic stroke (IS) and incident myocardial infarction (MI), meeting the FOURIER-like inclusion criteria were followed from date of diagnosis. Event rates were calculated for the hard major adverse cardiovascular events (MACE) composite: MI, IS, and CV death; and the ASCVD composite: MI, IS, unstable angina, coronary revascularization, and CV death. Approximately half of patients experienced a CV event (ASCVD composite) during follow-up. The MACE composite rates/100 person-years were 6.3, 11.9, and 12.3 in the ASCVD prevalent (n = 54 992), MI incident (n = 45 895), and IS incident (n = 36 134) cohorts, respectively. The ASCVD composite rates/100 person-years were 7.0, 21.7, and 12.9 in the ASCVD prevalent, MI incident, and IS incident cohorts, respectively. The multiple-event MACE composite rates/100 person-years were 8.5 (ASCVD prevalent cohort), 15.4 (MI incident cohort), and 14.4 (IS incident cohort).

Conclusion

In this real-world setting, CV event rates were high in all studied cohorts. In particular, the MACE composite rates were two to three times higher than in the FOURIER clinical trial, indicating a substantial disease burden despite treatment with moderate or high-intensity statins.

Patients with moderate chronic kidney disease without heart disease have reduced coronary flow velocity reserve

Aims

The overall aim was to identify sub‐clinical cardiac abnormalities by echocardiography in patients with chronic kidney disease (CKD) stages 3 and 4 and to investigate underlying mechanisms.

Methods and results

Ninety‐one patients with CKD stages 3 and 4, without a diagnosis of heart disease, and 41 healthy matched controls were included in this cross‐sectional study. Cardiac morphology and function were analysed with Doppler echocardiography and coronary flow velocity reserve (CFVR) in response to adenosine was measured in the left anterior descendent artery to detect coronary microvascular dysfunction (CMD). All study subjects had a left ventricular (LV) ejection fraction > 50%. Patients with CKD showed statistically significant increases in left atrial volume index and transmitral and pulmonary vein flow velocities during atrial contraction and prolonged LV isovolumetric relaxation time. Patients with CKD had significantly reduced CFVR vs. controls (2.74 ± 0.86 vs. 3.40 ± 0.89, P < 0.001), and 43% of patients were classified as having CMD compared with 9% of controls (P = 0.001).

Conclusions

Patients with CKD stages 3 and 4, without a diagnosis of heart disease, showed early abnormalities in LV diastolic function that did not fulfil the criteria for LV dysfunction according to current guidelines. A large proportion of CKD patients had CMD, suggesting that microvascular abnormalities may have a pathogenic role in the development of heart failure in this patient group.

Impact of Abdominal Aortic Calcification on Central Haemodynamics and Decline of Glomerular Filtration Rate in Patients with Chronic Kidney Disease Stages 3 and 4

BACKGROUND/AIM

Calcifications of large arteries are frequent in chronic kidney disease (CKD) and may contribute to the high cardiovascular risk in this population. The aim of this study was to examine whether abdominal aortic calcification volume (AACV) was a predictor of the rate of decline in glomerular filtration rate (GFR) in a cohort of patients with CKD stages 3 and 4.

METHODS

Eighty-four patients with CKD stages 3 and 4 were enrolled in this prospective observational study. At study entry, and annually, GFR was measured by plasma 51Cr-EDTA clearance. At baseline, haemodynamics was assessed and AACV was determined by computer tomography.

RESULTS

The mean follow-up time was 3.4 years and mean decline in GFR was -2.69 mL/min/1.73 m2 per year. At baseline, abdominal aortic calcification (AAC) was detected in 66 patients (79%). A binary logistic regression analysis revealed that age was the only statistically significant independent predictor of AAC. In patients with AAC, male gender (B = 0.413, p = 0.030), aortic diastolic blood pressure (B = -0.025, p = 0.001) and ankle-brachial index (B = -1.666, p = 0.002) were independently associated with AACV using a multiple linear regression analysis. Neither the presence nor the extent of AAC was significantly associated with the rate of change in GFR during follow-up.

CONCLUSION

In this cohort of patients with CKD stages 3 and 4, only age was an independent predictor of the presence of AAC. AACV was not associated with the rate of decline in GFR.

Body composition in patients with primary neuromuscular disease assessed by dual energy X-ray absorptiometry (DXA) and three different bioimpedance devices

BACKGROUND

Patients with primary neuromuscular disease have reduced muscle mass, and use of body mass index to assess nutritional status and body composition can therefore be questioned. Dual emission X-ray absorptiometry (DXA) can estimate muscle mass, but is not always readily available. Bioimpedance is a simple, portable and "easy to use" method for the assessment of body composition.

OBJECTIVES

To assess muscle mass by DXA in 143 patients with primary neuromuscular disease and validate three bioimpedance devices; Impedimed SFB7, (BIS_IMPEDIMED), Xitron4200 (BIS_XITRON) and Tanita MC180MA (MFBIA_TANITA).

METHODS

Body composition was assessed by DXA in 143, by BIS_IMPEDIMED in 116, by MFBIA_TANITA in 104 and by BIS_XITRON in 35 patients.

RESULTS

Muscle mass assessed by DXA, and phase angle (PhA) were below reference values in all female and 96% of male patients. BIS_IMPEDIMED underestimated muscle mass by 6.5 ± 14.2 kg (p < 0.001), but this could be corrected after exclusion of resistance (Ri) values > 3500 Ohm (p = 0.84). MFBIA_TANITA overestimated muscle mass by 30.8 ± 9.1 kg (p < 0.001) with systematic bias, whereas BIS_XITRON was in agreement with DXA, and without systematic bias. Muscle mass was strongly correlated to PhA (r_PEARSON = 0.75, p < 0.01).

CONCLUSION

Patients with primary neuromuscular disease have proportionally more fat and less muscle mass than the population in general, despite normal BMI. Muscle mass can be assessed by bioimpedance in these patients, but performance and bias depends on device. Phase angle by bioimpedance correlates to muscle mass, and could therefore potentially be used a surrogate measure of muscle mass during follow up.

Age- and sex-specific reference values for non-HDL cholesterol and remnant cholesterol derived from the Nordic Reference Interval Project (NORIP)

OBJECTIVES

Non-HDL-cholesterol (non-HDL-C) has been reported to be a better marker of cardiovascular risk than LDL-cholesterol (LDL-C) especially in individuals with high triglyceride values. Further, levels of remnant cholesterol have been suggested to in part explain residual risk not captured with LDL-C. The aim of the present study was to define reference values for non-HDL-C and remnant cholesterol based on data from the Nordic Reference Interval Project (NORIP).

METHODS

We analyzed the test results for total cholesterol, HDL-cholesterol and triglycerides from 1392 healthy females and 1236 healthy males. Non-HDL-C was calculated as measured total cholesterol minus measured HDL-cholesterol. Remnant cholesterol was calculated using the Friedewald equation for LDL-C: measured total cholesterol minus measured HDL-cholesterol and minus calculated LDL-cholesterol. The 2.5th and 97.5th percentiles for these markers were calculated according to the International Federation of Clinical Chemistry guidelines on the statistical treatment of reference values.

RESULTS

Age (18-<30, 30-49 and ≥50 years) and sex-specific reference intervals were calculated for non-HDL-cholesterol and remnant-cholesterol. Levels of non-HDL-C and remnant cholesterol differed between sex and age strata.

CONCLUSIONS

Age- and sex-specific reference intervals should be used for the triglyceride rich lipid variables non-HDL-C and remnant cholesterol. Since these markers may add information on risk burden beyond LDL-C, our hope is that these reference intervals will aid the introduction of automatic reporting of non-HDL-C by hospital laboratories.

Treatment target re-classification of subjects comparing estimation of low-density lipoprotein cholesterol by the Friedewald equation and direct measurement of LDL-cholesterol

AIMS

To compare low-density lipoprotein cholesterol (LDL-C) values calculated by the Friedewald equation with direct LDL-C in patient samples and assess the possible impact on re-classification of LDL-C target values for primary prevention or high cardiovascular disease (CVD) risk (<2.5 mmol/L) and secondary prevention or very high CVD risk (<1.8 mmol/L). LDL-C is an important CVD risk factor. Over the last decade, there has been a change in laboratory methodology from indirectly calculated LDL-C with the Friedewald equation to direct LDL-C measurements (dLDL-C).

METHODS

Reported results for plasma triglycerides, total cholesterol, high-density lipoprotein-cholesterol, and dLDL-C from 34,981 samples analyzed in year 2014 were extracted from the laboratory information system, Uppsala University Hospital, Uppsala, Sweden.

RESULTS

dLDL-C was approximately 10% lower than the corresponding LDL-C results calculated by the Friedewald equation in both men and women. In subjects with triglyceride concentrations above 4 mmol/L (n = 1250) the same discordant pattern was seen as for the entire study population. Altogether 5469 out of 18,051 men (30.3%) and 4604 out of 16,928 women (27.2%) were down-classified at least one CVD risk category. A very small number of subject was up-classified, in total 37 out of 18,051 men (0.2%) and 28 out of 16,928 women (0.2%).

CONCLUSIONS

The two LDL-C methods had a high concordance, but the direct LDL-C measurement consistently gave approx. 10% lower values, and this caused one-third of subjects to be re-classified as having a lower cardiovascular disease risk in relation to recommended LDL-C target values and decision limits.

Abdominal Aortic Calcifications Predict Survival in Peritoneal Dialysis Patients

BACKGROUND

Peripheral arterial disease and vascular calcifications contribute significantly to the outcome of dialysis patients. The aim of this study was to evaluate the prognostic role of severity of abdominal aortic calcifications and peripheral arterial disease on outcome of peritoneal dialysis (PD) patients using methods easily available in everyday clinical practice.

METHODS

We enrolled 249 PD patients (mean age 61 years, 67% male) in this prospective, observational, multicenter study from 2009 to 2013. The abdominal aortic calcification score (AACS) was assessed using lateral lumbar X ray, and the ankle-brachial index (ABI) using a Doppler device.

RESULTS

The median AACS was 11 (range 0 - 24). In 58% of the patients, all 4 segments of the abdominal aorta showed deposits, while 19% of patients had no visible deposits (AACS 0). Ankle-brachial index was normal in 49%, low (< 0.9) in 17%, and high (> 1.3) in 34% of patients. Altogether 91 patients (37%) died during the median follow-up of 46 months. Only 2 patients (5%) with AACS 0 died compared with 50% of the patients with AACS ≥ 7 (p < 0.001). The adjusted hazard ratio for all-cause mortality was 4.85 (95% confidence interval [CI] 1.94 - 24.46) for aortic calcification (AACS ≥ 7), 2.14 for diabetes (yes/no), 0.93 for albumin (per 1 g/L), and 1.04 for age (per year). A low or high ABI were not independently associated with mortality.

CONCLUSIONS

Severe aortic calcification was a strong predictor of all-cause mortality in PD patients. The evaluation of aortic calcifications by lateral X ray is a simple method that allows the identification of high-risk patients.

Overweight, hyperglycemia and tobacco use are modifiable risk factors for onset of retinopathy 9 and 17years after the diagnosis of diabetes - A retrospective observational nation-wide cohort study

BACKGROUND

The aims of this study were to estimate the risk for diabetic retinopathy (DR) and to identify risk factors. We investigated a nationwide population-based cohort with diabetes diagnosed at age 15-34years.

PATIENTS AND METHODS

Of 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) 444 (56%) patients with retinal photos available for classification of retinopathy participated in a follow-up study 15-19 (median 17) years after diagnosis. Mean age was 42.3±5.7years, BMI 26.1±4.1kg/m², 62% were male and 91% had type 1 diabetes. A sub-study was performed in 367 patients with retinal photos from both the 9 and 17year follow up and the risk for development of retinopathy between 9 and 17years of follow up was calculated.

RESULTS

After median 17years 324/444 (73%, 67% of T1D and 71% of T2D), had developed any DR but only 5.4% proliferative DR. Male sex increased the risk of developing retinopathy (OR 1.9, 95% CI 1.2-2.9). In the sub-study obesity (OR 1.2, 95% CI 1.04-1.4), hyperglycemia (OR 2.5, 95% CI 1.6-3.8) and tobacco use (OR 2.9, 95% CI 1.1-7.3) predicted onset of retinopathy between 9 and 17years after diagnosis of diabetes.

CONCLUSION

The number of patients with severe retinopathy after 17years of diabetes disease was small. The risk of developing retinopathy with onset between 9 and 17years after diagnosis of diabetes was strongly associated to modifiable risk factors such as glycemic control, obesity and tobacco use.

Reduced renal function in patients with Myotonic Dystrophy type 1 and the association to CTG expansion and other potential risk factors for chronic kidney disease

Myotonic dystrophy type 1 (DM1) affects several organs. Disease severity and age at onset are correlated to the CTG repeat expansion. The aim of this study was to assess renal function and the association to numbers of CTG repeat expansion in patients with DM1. Ninety-eight patients with DM1 were included. Glomerular filtration rate (measured GFR) was measured using iohexol clearance. Data on CTG repeats were available in 83/98 (85%) patients. The overall mGFR was 74 (16) ml/min/1.73 m² (range 38-134). Sixty-four patients (69%) had a mild and sixteen patients (17%) a moderate decrease in renal function (mGFR 60-89 and 30-59 ml/min/1.73 m², respectively). No correlations were found between CTG repeats and mGFR (r = 0.10, p = 0.4) or between CTG repeats and serum cystatin C (r = 0.12, p = 0.29). CTG repeats was positively correlated to creatinine-based estimates of GFR (eGFR) (modified diet in renal disease r = 0.49, p < 0.001, CKD-EPI creatinine equation; r = 0.50, p < 0.001), but analyses using Structural Equation Modeling showed no correlation. The correlation was explained by an indirect effect via serum creatinine and skeletal muscle mass index. In conclusion, patients with DM1 seem to have a slight decrease in renal function but there is no association between renal function and the number of CTG repeats, a marker of disease severity.

Decreased systolic blood pressure is associated with increased risk of all-cause mortality in patients with type 2 diabetes and renal impairment: A nationwide longitudinal observational study of 27,732 patients based on the Swedish National Diabetes Register

BACKGROUND

Previous studies have shown a U-shaped relationship between systolic blood pressure and risk of all-cause of mortality in patients with type 2 diabetes and renal impairment.

AIMS

To evaluate the associations between time-updated systolic blood pressure and time-updated change in systolic blood pressure during the follow-up period and risk of all-cause mortality in patients with type 2 diabetes and renal impairment.

PATIENTS AND METHODS

A total of 27,732 patients with type 2 diabetes and renal impairment in the Swedish National Diabetes Register were followed for 4.7 years. Time-dependent Cox models were used to estimate risk of all-cause mortality. Time-updated mean systolic blood pressure is the average of the baseline and the reported post-baseline systolic blood pressures.

RESULTS

A time-updated systolic blood pressure < 130 mmHg was associated with a higher risk of all-cause mortality in patients both with and without a history of chronic heart failure (hazard ratio: 1.25, 95% confidence interval: 1.13-1.40 and hazard ratio: 1.26, 1.17-1.36, respectively). A time-updated decrease in systolic blood pressure > 10 mmHg between the last two observations was associated with higher risk of all-cause mortality (-10 to -25 mmHg; hazard ratio: 1.24, 95% confidence interval: 1.17-1.32).

CONCLUSION

Both low systolic blood pressure and a decrease in systolic blood pressure during the follow-up are associated with a higher risk of all-cause mortality in patients with type 2 diabetes and renal impairment.

Role of cannabinoid receptor 1 in human adipose tissue for lipolysis regulation and insulin resistance

We recently showed that the peripheral cannabinoid receptor type 1 (CNR1) gene is upregulated by the synthetic glucocorticoid dexamethasone. CNR1 is highly expressed in the central nervous system and has been a drug target for the treatment of obesity. Here we explore the role of peripheral CNR1 in states of insulin resistance in human adipose tissue. Subcutaneous adipose tissue was obtained from well-controlled type 2 diabetes subjects and controls. Subcutaneous adipose tissue gene expression levels of CNR1 and endocannabinoid synthesizing and degrading enzymes were assessed. Furthermore, paired human subcutaneous adipose tissue and omental adipose tissue from non-diabetic volunteers undergoing kidney donation or bariatric surgery, was incubated with or without dexamethasone. Subcutaneous adipose tissue obtained from volunteers through needle biopsy was incubated with or without dexamethasone and in the presence or absence of the CNR1-specific antagonist AM281. CNR1 gene and protein expression, lipolysis and glucose uptake were evaluated. Subcutaneous adipose tissue CNR1 gene expression levels were 2-fold elevated in type 2 diabetes subjects compared with control subjects. Additionally, gene expression levels of CNR1 and endocannabinoid-regulating enzymes from both groups correlated with markers of insulin resistance. Dexamethasone increased CNR1 expression dose-dependently in subcutaneous adipose tissue and omental adipose tissue by up to 25-fold. Dexamethasone pre-treatment of subcutaneous adipose tissue increased lipolysis rate and reduced glucose uptake. Co-incubation with the CNR1 antagonist AM281 prevented the stimulatory effect on lipolysis, but had no effect on glucose uptake. CNR1 is upregulated in states of type 2 diabetes and insulin resistance. Furthermore, CNR1 is involved in glucocorticoid-regulated lipolysis. Peripheral CNR1 could be an interesting drug target in type 2 diabetes and dyslipidemia.

Soluble plasma proteins ST2 and CD163 as early biomarkers of nephropathy in Swedish patients with diabetes, 15-34 years of age: a prospective cohort study

BACKGROUND

The aim of this study was to investigate plasma levels of sST2 and sCD163 to determine whether they at an early stage could predict development of diabetic nephropathy and/or diabetic retinopathy in patients at clinical onset.

METHODS

Patients diagnosed with diabetes mellitus at age 15-34 years between 1987 and 1988 (n = 220) were included. Data such as BMI, smoking, HbA1c and islet cell antibodies were collected at time of diagnosis. Within the 10 year follow-up period, 112 patients (51%) developed following diabetes related complications; retinopathy (n = 91), nephropathy (n = 12) or both (n = 9). Plasma concentrations of sST2 and sCD163 were measured at time of diagnosis and levels compared between different complication groups.

RESULTS

Plasma levels of sST2 were significantly higher in patients who later developed nephropathy (n = 21; 1012 [773-1493] pg/ml) compared to those who did not (n = 199; 723 [449-1084] pg/ml; p = 0.006). A tendency for higher plasma levels of sCD163 was observed but not statistically significant (p = 0.058).

CONCLUSIONS

sST2 and sCD163 show promise as potential biomarkers for the development of nephropathy already at clinical onset. sST2 and/or sCD163 could possibly be part of a biomarker panel aimed to find patients at high risk of developing nephropathy. Both markers need to be investigated in a larger prospective study.

Alterations in heart rate variability during everyday life are linked to insulin resistance. A role of dominating sympathetic over parasympathetic nerve activity?

Aims

To evaluate the role of the autonomic nervous system (ANS) in the development of insulin resistance (IR) and assess the relationship between IR and activity of ANS using power spectrum analysis of heart rate variability (HRV).

Subjects and methods

Twenty-three healthy first-degree relatives of patients with type 2 diabetes (R) and 24 control subjects without family history of diabetes (C) group-matched for age, BMI and sex were included. Insulin sensitivity (M value) was assessed by hyperinsulinemic (56 mU/m²/min) euglycemic clamp. Activity of the ANS was assessed using power spectrum analysis of HRV in long-term recordings, i.e., 24-h ECG monitoring, and in short-term recordings during manoeuvres activating the ANS. Computed tomography was performed to estimate the amount and distribution of abdominal adipose tissue.

Results

Insulin sensitivity (M value, mg/kg lbm/min) did not differ significantly between the R and C groups. Total spectral power (P_tot) and very low-frequency (P_VLF) power was lower in R than C during 24 h ECG-recordings (p = 0.02 and p = 0.03). The best fit multiple variable linear regression model (r² = 0.37, p < 0.001 for model) indicated that body composition (BMI) and long-term low to high frequency (LF/HF) power ratio (std β = −0.46, p = 0.001 and std β = −0.28, p = 0.003, respectively) were significantly and independently associated with the M value.

Conclusion

Altered heart rate variability, assessed by power spectrum analysis, during everyday life is linked to insulin resistance. The data suggest that an increased ratio of sympathetic to parasympathetic nerve activity, occurring via both inherited and acquired mechanisms, could potentially contribute to the development of type 2 diabetes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12933-016-0411-8) contains supplementary material, which is available to authorized users.

Markers of fibrinolysis may predict development of lower extremity arterial disease in patients with diabetes: A longitudinal prospective cohort study with 10 years of follow-up

BACKGROUND

A previous cross-sectional study suggested that tissue plasminogen activator-activity might be an early marker of asymptomatic lower extremity arterial disease, but the long-term relationship is unknown.

SUBJECTS AND METHODS

This study included 96 diabetic (48 type 1/48 type 2) and 62 non-diabetic subjects aged 30-70 years without previously known lower extremity arterial disease (age: 50.3 ± 9.3 years, gender: M/W 47.5/52.5% and body mass index: 26.6 ± 4.5 kg/m(2)). The relationships between asymptomatic lower extremity arterial disease and fibrinolytic markers (tissue plasminogen activator-activity, tissue plasminogen activator-mass, plasminogen activator inhibitor-1 activity) at baseline and after 10 years were assessed by logistic regression analysis adjusting for age, hypertension, statin treatment, HbA1c, triglycerides and low-density lipoprotein cholesterol as fixed covariates.

RESULTS

The tissue plasminogen activator-activity at baseline and at the 10-year follow-up significantly predicted the presence of sign(s) of lower extremity arterial disease (odds ratio = 1.78, 95% confidence interval: 1.02-3.10, p = 0.043 and odds ratio = 1.78, 95% confidence interval: 1.12-2.23, p = 0.014, respectively). In addition, tissue plasminogen activator-mass at the 10-year follow-up was associated with signs of lower extremity arterial disease (odds ratio = 1.07, 95% confidence interval: 1.00-1.15, p = 0.046). Baseline age, hypertension and HbA1c were independently associated with sign(s) of lower extremity arterial disease at 10 years (odds ratio = 1.09, 95% confidence interval: 1.04-1.14, p = < 0.001; odds ratio = 3.68, 95% confidence interval: 1.67-8.12, p = 0.001 and odds ratio = 1.54, 95% confidence interval: 1.21-1.95, p = < 0.001, respectively).

CONCLUSION

This long-term study supports previous findings of a significant association between asymptomatic lower extremity arterial disease and tissue plasminogen activator-activity. Thus, tissue plasminogen activator-activity may be an early marker of lower extremity arterial disease although the mechanism of this relationship remains unclear.

Evaluation of reference genes for gene expression studies in human brown adipose tissue

Human brown adipose tissue (BAT) has during the last 5 year been subjected to an increasing research interest, due to its putative function as a target for future obesity treatments. The most commonly used method for molecular studies of human BAT is the quantitative polymerase chain reaction (qPCR). This method requires normalization to a reference gene (genes with uniform expression under different experimental conditions, e.g. similar expression levels between human BAT and WAT), but so far no evaluation of reference genes for human BAT has been performed. Two different microarray datasets with samples containing human BAT were used to search for genes with low variability in expression levels. Seven genes (FAM96B, GNB1, GNB2, HUWE1, PSMB2, RING1 and TPT1) identified by microarray analysis, and 8 commonly used reference genes (18S, B2M, GAPDH, LRP10, PPIA, RPLP0, UBC, and YWHAZ) were selected and further analyzed by quantitative PCR in both BAT containing perirenal adipose tissue and subcutaneous adipose tissue. Results were analyzed using 2 different algorithms (Normfinder and geNorm). Most of the commonly used reference genes displayed acceptably low variability (geNorm M-values <0.5) in the samples analyzed, but the novel reference genes identified by microarray displayed an even lower variability (M-values <0.25). Our data suggests that PSMB2, GNB2 and GNB1 are suitable novel reference genes for qPCR analysis of human BAT and we recommend that they are included in future gene expression studies of human BAT.

Blood pressure level and risk of major cardiovascular events and all-cause of mortality in patients with type 2 diabetes and renal impairment: an observational study from the Swedish National Diabetes Register

AIMS/HYPOTHESIS

We assessed the relationship between BP and risk of cardiovascular events (CVEs) and all-cause mortality in patients with type 2 diabetes and renal impairment (estimated GFR < 60 ml min(-1) 1.73 m(-2)) treated in clinical practice.

METHODS

A total of 33,356 patients (aged 75 ± 9 years, diabetes duration of 10 ± 8 years) with at least one serum creatinine and BP value available in the Swedish National Diabetes Register between 2005 and 2007 were followed up until 2011 or death. The relationships between mean BPs, CVEs and all-cause mortality were examined using time-dependent Cox models to estimate HRs, adjusting for cardiovascular risk factors and ongoing medications.

RESULTS

During the follow-up period (mean 5.3 years), 11,317 CVEs and 10,738 deaths occurred. The lowest risks of CVEs and all-cause mortality were observed with a systolic BP (SBP) of 135-139 and a diastolic BP (DBP) of 72-74 mmHg, and the highest risks were observed for those with SBP intervals 80-120 (CVE HR 2.3 [95% CI 2.0, 2.6] and all-cause mortality HR 2.4, [95% CI 2.1, 2.7]) and 160-230 mmHg (CVE HR 3.0 [95% CI 2.6, 3.3] and all-cause mortality HR 2.0 [95% CI 1.8-2.3]) and DBP intervals 40-63 mmHg (CVE HR 2.0 [95% CI 1.8, 2.2], all-cause mortality HR 2.0 [95% CI 1.8, 2.2]) and 83-125 mmHg (CVE HR 2.3 [95% CI 2.0, 2.5], all-cause mortality HR 2.3 [95% CI 2.0, 2.6]).

CONCLUSIONS/INTERPRETATION

In this nationwide cohort of patients with type 2 diabetes and renal impairment, the risk of CVEs and all-cause mortality increased significantly with both high and low BPs, while an SBP of 135-139 mmHg and DBP of 72-74 mmHg were associated with the lowest risks of CVEs and death.

The risk for diabetic nephropathy is low in young adults in a 17-year follow-up from the Diabetes Incidence Study in Sweden (DISS). Older age and higher BMI at diabetes onset can be important risk factors

AIMS

The main objective of this study was to estimate the occurrence of diabetic nephropathy in a population-based cohort of patients diagnosed with diabetes as young adults (15-34 years).

METHODS

All 794 patients registered 1987-1988 in the Diabetes Incidence Study in Sweden (DISS) were invited to a follow-up study 15-19 years after diagnosis, and 468 (58%) participated. Analysis of islet antibodies was used to classify type of diabetes.

RESULTS

After median 17 years of diabetes, 15% of all patients, 14% T1DM and 25% T2DM, were diagnosed with diabetic nephropathy. Ninety-one percent had microalbuminuria and 8.6% macroalbuminuria. Older age at diagnosis (HR 1.05; 95% CI 1.01-1.10 per year) was an independent and a higher BMI at diabetes diagnosis (HR 1.04; 95% CI 1.00-1.09 per 1 kg/m²), a near-significant predictor of development of diabetic nephropathy. Age at onset of diabetes (p = 0.041), BMI (p = 0.012) and HbA1c (p < 0.001) were significant predictors of developing diabetic nephropathy between 9 and 17 years of diabetes. At 17 years of diabetes duration, a high HbA1c level (OR 1.06; 95% CI 1.03-1.08 per 1 mmol/mol increase) and systolic blood pressure (OR 1.08; 95% CI 1.05 1.12 per 1 mmHg increase) were associated with DN.

CONCLUSIONS

Patients with T2DM diagnosed as young adults seem to have an increased risk to develop diabetic nephropathy compared with those with T1DM. Older age and higher BMI at diagnosis of diabetes were risk markers for development of diabetic nephropathy. In addition, poor glycaemic control but not systolic blood pressure at 9 years of follow-up was a risk marker for later development of diabetic nephropathy.

Cyclosporine A and tacrolimus reduce the amount of GLUT4 at the cell surface in human adipocytes: increased endocytosis as a potential mechanism for the diabetogenic effects of immunosuppressive agents

CONTEXT

Immunosuppressive agents are associated with profound metabolic side effects including new-onset diabetes and dyslipidemia after organ transplantation.

OBJECTIVE

To investigate the effects of cyclosporine A (CsA) and tacrolimus on glucose uptake and insulin signaling in human adipocytes and their impact on the regulation of cellular trafficking of the glucose transporter 4 (GLUT4).

DESIGN

Isolated human adipocytes were incubated with therapeutic concentrations of either CsA or tacrolimus, and glucose uptake and expression of insulin signaling proteins were assessed. Furthermore, we studied effects of CsA and tacrolimus on the regulation of cellular trafficking of GLUT4 in differentiated human preadipocytes and L6 cells.

RESULTS

CsA and tacrolimus had a concentration-dependent inhibitory effect on basal and insulin-stimulated (14)C-glucose uptake in adipocytes. Although phosphorylation at Tyr1146 of the insulin receptor was inhibited by tacrolimus, the phosphorylation and/or protein levels of the insulin signaling proteins IRS1/2, p85-PI3K, PKB, AS160, and mTORC1, as well as GLUT4 and GLUT1, were unchanged by CsA or tacrolimus. Furthermore, CsA and tacrolimus reduced the GLUT4 amount localized at the cell surface of differentiated human preadipocytes and L6 cells in the presence of insulin. This occurred by an increased rate of GLUT4 endocytosis, with no change in the exocytosis rate.

CONCLUSIONS

These results suggest that therapeutic concentrations of CsA and tacrolimus can inhibit glucose uptake independent of insulin signaling by removing GLUT4 from the cell surface via an increased rate of endocytosis. This mechanism can contribute to the development of insulin resistance and diabetes associated with immunosuppressive therapy. In addition, it may provide novel pharmacological approaches for the treatment of diabetes.

A case report of improved metabolic control after conversion from everolimus to cyclosporin A: role of adipose tissue mechanisms?

BACKGROUND

New-onset diabetes after transplantation is associated with an increase in risk of graft failure, cardiovascular disease, and mortality. Therefore, it compromises the overall beneficial outcome of organ transplantation.

CASE REPORT

A patient with new-onset diabetes after renal transplantation showed glucose and lipid metabolism improvements after switching immunosuppressant from everolimus to cyclosporin A. A subcutaneous adipose tissue biopsy displayed changes in gene and protein expression that could contribute to the clinical improvement of hyperglycemia and dyslipidemia.

FKBP5 expression in human adipose tissue increases following dexamethasone exposure and is associated with insulin resistance

OBJECTIVE

To study effects of dexamethasone on gene expression in human adipose tissue aiming to identify potential novel mechanisms for glucocorticoid-induced insulin resistance.

MATERIALS/METHODS

Subcutaneous and omental adipose tissue, obtained from non-diabetic donors (10 M/15 F; age: 28-60 years; BMI: 20.7-30.6 kg/m²), was incubated with or without dexamethasone (0.003-3 μmol/L) for 24 h. Gene expression was assessed by microarray and real time-PCR and protein expression by immunoblotting.

RESULTS

FKBP5 (FK506-binding protein 5) and CNR1 (cannabinoid receptor 1) were the most responsive genes to dexamethasone in both subcutaneous and omental adipose tissue (~7-fold). Dexamethasone increased FKBP5 gene and protein expression in a dose-dependent manner in both depots. The gene product, FKBP51 protein, was 10-fold higher in the omental than in the subcutaneous depot, whereas the mRNA levels were similar. Higher FKBP5 gene expression in omental adipose tissue was associated with reduced insulin effects on glucose uptake in both depots. Furthermore, FKBP5 gene expression in subcutaneous adipose tissue was positively correlated with serum insulin, HOMA-IR and subcutaneous adipocyte diameter and negatively with plasma HDL-cholesterol. FKBP5 SNPs were found to be associated with type 2 diabetes and diabetes-related phenotypes in large population-based samples.

CONCLUSIONS

Dexamethasone exposure promotes expression of FKBP5 in adipose tissue, a gene that may be implicated in glucocorticoid-induced insulin resistance.

Altered DNA methylation and differential expression of genes influencing metabolism and inflammation in adipose tissue from subjects with type 2 diabetes

Genetics, epigenetics, and environment may together affect the susceptibility for type 2 diabetes (T2D). Our aim was to dissect molecular mechanisms underlying T2D using genome-wide expression and DNA methylation data in adipose tissue from monozygotic twin pairs discordant for T2D and independent case-control cohorts. In adipose tissue from diabetic twins, we found decreased expression of genes involved in oxidative phosphorylation; carbohydrate, amino acid, and lipid metabolism; and increased expression of genes involved in inflammation and glycan degradation. The most differentially expressed genes included ELOVL6, GYS2, FADS1, SPP1 (OPN), CCL18, and IL1RN. We replicated these results in adipose tissue from an independent case-control cohort. Several candidate genes for obesity and T2D (e.g., IRS1 and VEGFA) were differentially expressed in discordant twins. We found a heritable contribution to the genome-wide DNA methylation variability in twins. Differences in methylation between monozygotic twin pairs discordant for T2D were subsequently modest. However, 15,627 sites, representing 7,046 genes including PPARG, KCNQ1, TCF7L2, and IRS1, showed differential DNA methylation in adipose tissue from unrelated subjects with T2D compared with control subjects. A total of 1,410 of these sites also showed differential DNA methylation in the twins discordant for T2D. For the differentially methylated sites, the heritability estimate was 0.28. We also identified copy number variants (CNVs) in monozygotic twin pairs discordant for T2D. Taken together, subjects with T2D exhibit multiple transcriptional and epigenetic changes in adipose tissue relevant to the development of the disease.

Characterization of brown adipose tissue in the human perirenal depot

OBJECTIVE

To characterize brown adipose tissue (BAT) in the human perirenal adipose tissue depot.

METHOD

Perirenal adipose tissue biopsies were obtained from 55 healthy kidney donors. Expression analysis was performed using microarray, real-time PCR, immunoblotting and immunohistochemistry. Additional studies using human stem cells were performed.

RESULTS

UCP1 gene expression analysis revealed a large intra-individual variation in the perirenal adipose tissue biopsies. Both multi- and unilocular UCP1-positive adipocytes were detected in several of the adipose tissue samples analyzed by immunohistochemical staining. Microarray analysis identified 54 genes that were overexpressed in UCP1-positive perirenal adipose tissue. Real-time PCR analysis of BAT candidate genes revealed a set of genes that were highly correlated to UCP1 and a set of three transcription factor genes (PRDM16, PGC1α, and RXRγ) that were highly correlated to each other. RXRγ displayed nuclear immunoreactivity in brown adipocytes and an increased gene expression during brown adipogenesis in human stem cells.

CONCLUSION

Our data provides the first molecular characterization of BAT in the perirenal adipose tissue depot. Furthermore, it highlights the transcription factor RXRγ as a new player in BAT development.

Differences between men and women in the regulation of adipose 11β-HSD1 and in its association with adiposity and insulin resistance

This study explored sex differences in 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) activity and gene expression in isolated adipocytes and adipose tissue (AT), obtained via subcutaneous biopsies from non-diabetic subjects [58 M, 64 F; age 48.3 ± 15.3 years, body mass index (BMI) 27.2 ± 3.9 kg/m²]. Relationships with adiposity and insulin resistance (IR) were addressed. Males exhibited higher 11β-HSD1 activity in adipocytes than females, but there was no such difference for AT. In both men and women, adipocyte 11β-HSD1 activity correlated positively with BMI, waist circumference, % body fat, adipocyte size and with serum glucose, triglycerides and low-density lipoprotein:high-density lipoprotein (LDL:HDL) ratio. Positive correlations with insulin, HOMA-IR and haemoglobin A1c (HbA1c) and a negative correlation with HDL-cholesterol were significant only in males. Conversely, 11β-HSD1 activity in AT correlated with several markers of IR and adiposity in females but not in males, but the opposite pattern was found with respect to 11β-HSD1 mRNA expression. This study suggests that there are sex differences in 11β-HSD1 regulation and in its associations with markers of obesity and IR.

Albuminuria and renal function as predictors of cardiovascular events and mortality in a general population of patients with type 2 diabetes: a nationwide observational study from the Swedish National Diabetes Register

OBJECTIVE

Reduced renal function and albuminuria predict cardiovascular (CV) events and mortality in type 2 diabetes (T2D). In addition, we evaluated the role of co-existing congestive heart failure (CHF) and other CV risk factors on CV events in a large observational population-based cohort of T2D patients.

RESEARCH DESIGN AND METHODS

We included 66,065 patients with T2D who were reported to the National Diabetes Register (NDR) in Sweden between 2003-2006 with a follow-up of 5.7 years. Data on outcomes were collected from the cause of death and hospital discharge registers.

RESULTS

A total of 10% of patients experienced a CV event and 3.7% of these were fatal. Increasing levels of albuminuria and renal impairment were independently associated with increasing risk of CV events and all-cause mortality also when adjusting for CHF. In normoalbuminuric patients, a reduction in renal function is an important predictor of CV events and all-cause mortality. Glycaemic control (high HbA1c), smoking and hyperlipidaemia had important effects on risk for CV events in patients with albuminuria, while high blood pressure, but not glycaemic control, had an effect in patients with normoalbuminuric renal impairment.

CONCLUSION

Albuminuria and renal impairment are independent risk factors for CV outcomes and mortality in T2D, albuminuria being the strongest risk factor and relevant at all levels of renal function. In normoalbuminuric patients, a reduction in renal function is an important predictor of CV events and all-cause mortality.

Ongoing treatment with renin-angiotensin-aldosterone-blocking agents does not predict normoalbuminuric renal impairment in a general type 2 diabetes population

AIM

To examine the prevalence and the clinical characteristics associated with normoalbuminuric renal impairment (RI) in a general type 2 diabetes (T2D) population.

METHODS

We included 94 446 patients with T2D (56% men, age 68.3±11.6 years, BMI 29.6±5.3 kg/m², diabetes duration 8.5±7.1 years; means±SD) with renal function (serum creatinine) reported to the Swedish National Diabetes Register (NDR) in 2009. RI was defined as estimated glomerular filtration (eGFR)<60 ml/min/1.73 m² and albuminuria as a urinary albumin excretion rate (AER) >20 μg/min. We linked the NDR to the Swedish Prescribed Drug Register, and the Swedish Cause of Death and the Hospital Discharge Register to evaluate ongoing medication and clinical outcomes.

RESULTS

17% of the patients had RI, and 62% of these patients were normoalbuminuric. This group of patients had better metabolic control, lower BMI, lower systolic blood pressure and were more often women, non-smokers and more seldom had a history of cardiovascular disease as compared with patients with albuminuric RI. 28% of the patients with normoalbuminuric RI had no ongoing treatment with any RAAS-blocking agent. Retinopathy was most common in patients with RI and albuminuria (31%).

CONCLUSIONS

The majority of patients with type 2 diabetes and RI were normoalbuminuric despite the fact that 25% of these patients had no ongoing treatment with RAAS-blocking agents. Thus, RI in many patients with type 2 diabetes is likely to be caused by other factors than diabetic microvascular disease and ongoing RAAS-blockade.

The immunosuppressive agents rapamycin, cyclosporin A and tacrolimus increase lipolysis, inhibit lipid storage and alter expression of genes involved in lipid metabolism in human adipose tissue

Cyclosporin A (CsA), tacrolimus and rapamycin are immunosuppressive agents (IAs) associated with insulin resistance and dyslipidemia, although their molecular effects on lipid metabolism in adipose tissue are unknown. We explored IAs effects on lipolysis, lipid storage and expression of genes involved on lipid metabolism in isolated human adipocytes and/or adipose tissue obtained via subcutaneous and omental fat biopsies. CsA, tacrolimus and rapamycin increased isoproterenol-stimulated lipolysis and inhibited lipid storage by 20-35% and enhanced isoproterenol-stimulated hormone-sensitive lipase Ser552 phosphorylation. Rapamycin also increased basal lipolysis (~20%) and impaired insulin's antilipolytic effect. Rapamycin, down-regulated the gene expression of perilipin, sterol regulatory element-binding protein 1 (SREBP1) and lipin 1, while tacrolimus down-regulated CD36 and aP2 gene expression. All three IAs increased IL-6 gene expression and secretion, but not expression and secretion of TNF-α or adiponectin. These findings suggest that CsA, tacrolimus and rapamycin enhance lipolysis, inhibit lipid storage and expression of lipogenic genes in adipose tissue, which may contribute to the development of dyslipidemia and insulin resistance associated with immunosuppressive therapy.

End-stage renal disease and low level exposure to lead, cadmium and mercury; a population-based, prospective nested case-referent study in Sweden

BACKGROUND

Cadmium (Cd), lead (Pb), and mercury (Hg) cause toxicological renal effects, but the clinical relevance at low-level exposures in general populations is unclear. The objective of this study is to assess the risk of developing end-stage renal disease in relation to Cd, Pb, and Hg exposure.

METHODS

A total of 118 cases who later in life developed end-stage renal disease, and 378 matched (sex, age, area, and time of blood sampling) referents were identified among participants in two population-based prospective cohorts (130,000 individuals). Cd, Pb, and Hg concentrations were determined in prospectively collected samples.

RESULTS

Erythrocyte lead was associated with an increased risk of developing end-stage renal disease (mean in cases 76 μg/L; odds ratio (OR) 1.54 for an interquartile range increase, 95% confidence interval (CI) 1.18-2.00), while erythrocyte mercury was negatively associated (2.4 μg/L; OR 0.75 for an interquartile range increase, CI 0.56-0.99). For erythrocyte cadmium, the OR of developing end-stage renal disease was 1.15 for an interquartile range increase (CI 0.99-1.34; mean Ery-Cd among cases: 1.3 μg/L). The associations for erythrocyte lead and erythrocyte mercury, but not for erythrocyte cadmium, remained after adjusting for the other two metals, smoking, BMI, diabetes, and hypertension. Gender-specific analyses showed that men carried almost all of the erythrocyte lead and erythrocyte cadmium associated risks.

CONCLUSIONS

Erythrocyte lead is associated with end-stage renal disease but further studies are needed to evaluate causality. Gender-specific analyses suggest potential differences in susceptibility or in exposure biomarker reliability.

mTOR inhibition with rapamycin causes impaired insulin signalling and glucose uptake in human subcutaneous and omental adipocytes

Rapamycin is an immunosuppressive agent used after organ transplantation, but its molecular effects on glucose metabolism needs further evaluation. We explored rapamycin effects on glucose uptake and insulin signalling proteins in adipocytes obtained via subcutaneous (n=62) and omental (n=10) fat biopsies in human donors. At therapeutic concentration (0.01 μM) rapamycin reduced basal and insulin-stimulated glucose uptake by 20-30%, after short-term (15 min) or long-term (20 h) culture of subcutaneous (n=23 and n=10) and omental adipocytes (n=6 and n=7). Rapamycin reduced PKB Ser473 and AS160 Thr642 phosphorylation, and IRS2 protein levels in subcutaneous adipocytes. Additionally, it reduced mTOR-raptor, mTOR-rictor and mTOR-Sin1 interactions, suggesting decreased mTORC1 and mTORC2 formation. Rapamycin also reduced IR Tyr1146 and IRS1 Ser307/Ser616/Ser636 phosphorylation, whereas no effects were observed on the insulin stimulated IRS1-Tyr and TSC2 Thr1462 phosphorylation. This is the first study to show that rapamycin reduces glucose uptake in human adipocytes through impaired insulin signalling and this may contribute to the development of insulin resistance associated with rapamycin therapy.