Diabetic dyslipidaemia

Microalbuminuria and lipid variations in adolescents diagnosed with type 1 diabetes

Objective

This study investigates the prevalence of lipid abnormalities among adolescents diagnosed with Type 1 Diabetes Mellitus (T1DM) and explores potential associations with microalbuminuria and cardiovascular disease (CVD) risk factors.Research Design and Methods: A retrospective study analyzed lipid profiles, microalbuminuria, and CVD risk in adolescents with T1DM. Six hundred individuals were assessed for lipid levels, BMI, and microalbuminuria.

Results

Dyslipidemia prevalence was 59.7 %, with 22.7 % exhibiting abnormal total cholesterol (TC) and triglycerides (TG), and 15.8 % with elevated TC alone. A2 microalbuminuria was found in 59.2 %, with 14.6 % showing A3. Females had higher A2 prevalence and mild eGFR decrease (P = 0.02). Lipid levels correlated significantly with microalbuminuria (TC: r = 0.761; TG: r = 0.572, P = 0.03 and 0.04, respectively). The prevalence of high total cholesterol (TC) + high triglycerides (TG), as well as the high TG alone, was considerably higher in patients belonging to the A2 Microalbuminuria group. AIP, HbA1c, and UACR showed a strong positive correlation (r = 0.542, P = 0.04; r = 0.621, P = 0.02).

Conclusion

Our study highlights the prevalence of elevated or borderline lipid levels among adolescents with Type 1 Diabetes Mellitus (T1DM), indicating a heightened risk of dyslipidemia in this population. Particularly concerning is the significantly increased incidence of dyslipidemia among young individuals with T1DM, with females exhibiting a notable susceptibility to cardiovascular disease (CVD) due to dyslipidemia's impact on the Atherogenic Index of Plasma (AIP). Furthermore, Microalbuminuria, specifically type A2 and A3, was prevalent among our study participants, with females showing a significantly higher occurrence of A2 microalbuminuria compared to males. The association between microalbuminuria and dyslipidemia, especially the combination of high total cholesterol (TC) and high triglycerides (TG), emphasizes the importance of comprehensive screening protocols for both microalbuminuria and dyslipidemia in managing the cardiovascular risk profile of individuals with T1DM.

Sex Difference Impacts on the Relationship between Paraoxonase-1 (PON1) and Type 2 Diabetes

Type-2 diabetes (T2D) and its cardiovascular complications are related to sex. Increasing evidence suggests that paraoxonase 1 (PON1) activity, an antioxidant enzyme bound to high-density lipoproteins (HDL), is implicated in the onset and clinical progression of T2D. Since we previously showed that PON1 is a sexual dimorphic protein, we now investigated whether sex might impact the relationship between PON1 and this chronic disease. To address this aim, we assessed PON1 activity in the sera of 778 patients, including controls (women, n = 383; men, n = 198) and diabetics (women, n = 79; men = 118). PON1 activity decreased in both women and men with T2D compared with controls (p < 0.05 and p > 0.001, respectively), but the change was 50% larger in the female cohort. In line with this result, the enzyme activity was associated with serum glucose level only in women (r = -0.160, p = 0.002). Notably, only within this gender category, lower PON1 activity was independently associated with increased odds of being diabetic (odds ratio (95% Confidence interval: 2.162 (1.075-5.678)). In conclusion, our study suggests that PON1-deficiency in T2D is a gender-specific phenomenon, with women being more affected than men. This could contribute to the partial loss of female cardiovascular advantage associated with T2D.

Association analysis of dyslipidemia-related genes in diabetic nephropathy

Type 1 diabetes (T1D) increases risk of the development of microvascular complications and cardiovascular disease (CVD). Dyslipidemia is a common risk factor in the pathogenesis of both CVD and diabetic nephropathy (DN), with CVD identified as the primary cause of death in patients with DN. In light of this commonality, we assessed single nucleotide polymorphisms (SNPs) in thirty-seven key genetic loci previously associated with dyslipidemia in a T1D cohort using a case-control design. SNPs (n = 53) were genotyped using Sequenom in 1467 individuals with T1D (718 cases with proteinuric nephropathy and 749 controls without nephropathy i.e. normal albumin excretion). Cases and controls were white and recruited from the UK and Ireland. Association analyses were performed using PLINK to compare allele frequencies in cases and controls. In a sensitivity analysis, samples from control individuals with reduced renal function (estimated glomerular filtration rate<60 ml/min/1.73 m²) were excluded. Correction for multiple testing was performed by permutation testing. A total of 1394 samples passed quality control filters. Following regression analysis adjusted by collection center, gender, duration of diabetes, and average HbA1c, two SNPs were significantly associated with DN. rs4420638 in the APOC1 region (odds ratio [OR]  = 1.51; confidence intervals [CI]: 1.19–1.91; P = 0.001) and rs1532624 in CETP (OR = 0.82; CI: 0.69–0.99; P = 0.034); rs4420638 was also significantly associated in a sensitivity analysis (P = 0.016) together with rs7679 (P = 0.027). However, no association was significant following correction for multiple testing. Subgroup analysis of end-stage renal disease status failed to reveal any association. Our results suggest common variants associated with dyslipidemia are not strongly associated with DN in T1D among white individuals. Our findings, cannot entirely exclude these key genes which are central to the process of dyslipidemia, from involvement in DN pathogenesis as our study had limited power to detect variants of small effect size. Analysis in larger independent cohorts is required.

Statin utilization according to indication and age: a Danish cohort study on changing prescribing and purchasing behaviour

OBJECTIVE

Introduced to reduce mortality after myocardial infarction (MI), statins are now recommended for a range of other conditions, including asymptomatic individuals without cardiovascular disease or diabetes. The aim was to describe trends in Danish statin utilization according to indication and age during 1996-2009, and to analyse changing prescribing and purchasing behaviour during time intervals (driver periods) a priori defined by potential influential factors.

METHODS

A nationwide cohort (N=4,998,580) was followed in Danish individual-level registries. Based on a hierarchy of register markers of indications for statin prescribing, we analysed incidence and prevalence of use by age and indication (age ≥ 40). Applying Poisson regression, we calculated Incidence Rate Ratios (IRR) of statin treatment for the last year of each driver period, applying the first year as reference.

RESULTS

Treatment prevalence increased from 7/1000 to 187/1000, representing a shift towards lower-level indications and increased relatively more in individuals aged 75+. While treatment prevalence in MI-patients reached 780/1000, asymptomatic individuals represented 50% of incident statin-users in 2009. A marked increase in incidence of statin use occurred during 1999-2003 (IRR=3.05) across all indications, followed by a more moderate rise during 2003-2006 (IRR=1.29) and 2006-2008 (IRR=1.15) - most marked increases in asymptomatic individuals. A sudden decrease was observed in 2009 (IRR=0.82) for all indications and ages.

CONCLUSION

While patent expiry and lower prices most likely boosted the general increase in statin utilization, the gradually altered indication and age pattern seems to be driven by guidelines, influencing both reimbursement rules and general healthcare policies. A media debate on statin side effects may have modified the general attitudes.

An independent effect of parental lipids on the offspring lipid levels in a cohort of adolescents with type 1 diabetes

BACKGROUND

Genetic factors modulate lipid levels and an intrafamilial aggregation of abnormal lipid profiles has been reported in the general population. As dyslipidemia is common among people with diabetes and has been related to diabetic nephropathy, we investigated whether parental lipid levels were related to lipids and albumin excretion in young offspring with childhood-onset type 1 diabetes (T1D).

METHODS

Non-fasting blood samples were collected from 895 offspring, 808 mothers and 582 fathers. Total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) and non-HDL-C were measured. Three early morning urinary albumin-creatinine ratios (ACR), hemoglobin A1C (HbA1c) and anthropometric parameters were also assessed.

RESULTS

The offspring's mean age (±SD) was 14.5 ± 2.2 yr, mean diabetes duration 5.5 ± 3.7 yr; the fathers' age was 45.7 ± 6.1 yr and the mothers' age was 42.8 ± 5.5 yr. After adjusting for the offspring age, gender, body mass index, HbA1c, maternal (TC: β = 0.242; TG: β = 0.152; HDL-C: β = 0.285; LDL-C: β = 0.278; non-HDL-C: β = 0.253; all p < 0.001) and paternal lipid levels (TC: β = 0.188; TG: β = 0.108; HDL-C: β = 0.253; LDL-C: β = 0.187; non-HDL-C: β = 0.173; all p < 0.001) were significantly associated with the offspring's lipid parameters. In contrast, no significant association was found between parental lipid levels and the offspring's ACR.

CONCLUSIONS

In the present study, parental lipid levels were independently associated with the same traits in the offspring, suggesting a role of genetic influences and/or shared environmental factors in modulating the metabolic profile of adolescents with T1D. In contrast, there was no significant association between parental lipid levels and the offspring's albumin excretion.

Prevalence of abnormal lipid profiles and the relationship with the development of microalbuminuria in adolescents with type 1 diabetes

OBJECTIVE

To explore the prevalence of lipid abnormalities and their relationship with albumin excretion and microalbuminuria in adolescents with type 1 diabetes.

RESEARCH DESIGN AND METHODS

The study population comprised 895 young subjects with type 1 diabetes (490 males); median age at the baseline assessment was 14.5 years (range 10-21.1), and median diabetes duration was 4.8 years (0.2-17). A total of 2,194 nonfasting blood samples were collected longitudinally for determination of total cholesterol, LDL cholesterol, HDL cholesterol, TG, and non-HDL cholesterol. Additional annually collected data on anthropometric parameters, A1C, and albumin-to-creatinine ratio (ACR) were available.

RESULTS

Total cholesterol, LDL cholesterol, HDL cholesterol, and non-HDL cholesterol were higher in females than in males (all P < 0.001). A significant proportion of subjects presented sustained lipid abnormalities during follow-up: total cholesterol >5.2 mmol/l (18.6%), non-HDL cholesterol >3.4 mmol/l (25.9%), TG >1.7 mmol/l (20.1%), and LDL cholesterol >3.4 mmol/l (9.6%). Age and duration were significantly related to all lipid parameters (P < 0.001); A1C was independently related to all parameters (P < 0.001) except HDL cholesterol, whereas BMI SD scores were related to all parameters (P < 0.05) except total cholesterol. Total cholesterol and non-HDL cholesterol were independently related to longitudinal changes in ACR (B coefficient +/- SE): 0.03 +/- 0.01/1 mmol/l, P = 0.009, and 0.32 +/- 0.014/1 mmol/l, P = 0.02, respectively. Overall mean total cholesterol and non-HDL cholesterol were higher in microalbuminuria positive (n = 115) than in normoalbuminuric subjects (n = 780): total cholesterol 4.7 +/- 1.2 vs. 4.5 +/- 0.8 mmol/l (P = 0.04) and non-HDL cholesterol 3.2 +/- 1.2 vs. 2.9 +/- 0.8 mmol/l (P = 0.03).

CONCLUSIONS

In this longitudinal study of adolescents with type 1 diabetes, sustained lipid abnormalities were related to age, duration, BMI, and A1C. Furthermore, ACR was related to both total cholesterol and non-HDL cholesterol, indicating a potential role in the pathogenesis of diabetic nephropathy.

Relationship between lipid profiles and kidney function in patients with type 1 diabetes

AIMS/HYPOTHESIS

We studied the relationship between the lipid profile, estimated GFR (eGFR) and AER in patients with type 1 diabetes. We also assessed the association between the lipid profile and glycaemic control, obesity and hypertension in an environment free of manifest renal disease, as well as exploring how well the patients would have achieved the targets set in international guidelines.

METHODS

A total of 2,927 adult patients who had type 1 diabetes and for whom lipid profiles were available were included from people participating in the nationwide, multicentre Finnish Diabetic Nephropathy Study (FinnDiane). eGFR was determined using the Cockcroft-Gault formula adjusted for body surface area.

RESULTS

Patients with impaired renal function (eGFR <60 ml min(-1) 1.73 m(-2)) had higher total cholesterol, triacylglycerol and apolipoprotein B, and lower HDL-cholesterol concentrations than patients with normal renal function (eGFR >90 ml min(-1) 1.73 m(-2)) or mildly impaired renal function (eGFR 60-90 ml min(-1) 1.73 m(-2)) (p < 0.001 for all associations). In type 1 diabetic patients without manifest renal disease, similar adverse lipid profiles could be observed in those who were overweight or obese and in those who had intermediate or poor glycaemic control or hypertension. In all the different patient groups 14 to 43% would have achieved the recommended target of <2.6 mmol/l for LDL-cholesterol.

CONCLUSIONS/INTERPRETATION

Multiple lipid abnormalities are not only present in type 1 diabetic patients with an abnormal AER, but also in those with impaired renal function. In patients without manifest renal disease, obesity, glycaemic control or hypertension were associated with an adverse lipid profile. A substantial number of patients studied would have exceeded the targets set by international guidelines, particularly the targets for LDL-cholesterol.

Impact of migration on coronary heart disease risk factors: comparison of Gujaratis in Britain and their contemporaries in villages of origin in India

The causes of the excess coronary heart disease (CHD) risk in South Asian migrants from the Indian subcontinent remain unclear. Comparisons of CHD risk factors amongst South Asian migrants living in Britain with those of the general UK population provide only a partial explanation. We compared Gujaratis in Britain with similar, non-migrant Gujaratis in India, to test the hypothesis that differences in CHD risk factors associated with migration would be more informative. Randomly sampled Gujaratis aged 25-79 years living in Sandwell (n = 242) were compared with age-, gender- and caste-matched contemporaries remaining in their villages of origin in Navsari, India (n = 295). Lifestyle indices, food intake and physical activity, were assessed with standardised questionnaires and energy expenditure and metabolic parameters measured. British Gujaratis had higher, mean body mass indices by 6 (4.5-7.4) kg/m(2) mean (95% CI), and greater dietary energy intake, fat intake, blood pressure, fasting serum cholesterol, apolipoprotein B, triglycerides, non-esterified fatty acid (NEFA) and C-reative protein concentrations than Gujaratis in India. Dietary folate and serum folate and Vitamin B(12) were lower and plasma homocysteine was higher in India. Smoking was less prevalent and high-density lipoprotein cholesterol tended to be higher in Britain. Diabetes prevalence was high in both populations and impaired fasting or 2 h post-glucose challenge plasma glucose was even more prevalent in Gujarat. In India, however, where insulin secretion and NEFA were lower diabetes and impaired glucose tolerance were less frequently accompanied by excess metabolic CVD risk factors. In conclusion, exposure to increased fat intake and obesity related to migration is likely to explain the disproportionate combination of established and emerging CHD risk factors prevalent in Gujaratis in Britain. Strategies to improve nutrition and to identify and treat cardiovascular risk factors such as dyslipidaemia and hypertension are urgently required.

Effects of a Novel Anti-Hyperlipidemic Agent, S-2E, on Blood Lipid Levels in Rats with Fructose-Induced Hypertriglyceridemia

Using rats with fructose-induced hypertriglyceridemia, an animal model of human hypertriglyceridemia, we investigated whether (+)-(S)-p-[1-(p-tert-butylphenyl)-2-oxo-4-pyrrolidinyl]-methoxybenzoic acid (S-2E), a novel anti-hyperlipidemic agent, reduced the elevated levels of triglyceride (TG) and non-high-density lipoprotein cholesterol (non-HDL-C), and then whether it elevated HDL-C levels. At doses of 3-30 mg/kg, S-2E reduced elevated TG levels and non-HDL-C levels simultaneously in a dose-dependent manner after a week. Furthermore, S-2E treatment at 10 mg/kg for 4 weeks showed similar effects, while the elongation of intervals between feeding periods led to further increases in these levels. Interestingly, S-2E increased blood HDL-C levels after 4 weeks of treatment. It is therefore reasonable to assume that S-2E may be useful to improve dyslipidemia such as hypertriglyceridemia and low levels of HDL-C.

Prevention and treatment of diabetic nephropathy in older patients

Renal disease in older diabetic patients is costly in terms of morbidity, mortality and expenditure. Therefore, prevention and treatment of diabetic nephropathy has become a prominent goal in the treatment of patients with diabetes mellitus. Preventive treatment should begin no later than at the stage of microalbuminuria, and regular screening for microalbuminuria is recommended for all patients with diabetes, irrespective of age. Improved metabolic control has been demonstrated to lower urinary albumin excretion. Target glycosylated haemoglobin levels should be below 7%, or 1% above the upper limit of normal of non-diabetic subjects. The use of an intensified treatment regimen is recommended. Insulin therapy has no adverse effects on renal indexes. To preserve renal function in older diabetic patients, blood pressure should be kept at or below 130/80 mm Hg. Treatment with ACE inhibitors or angiotensin II receptor antagonists (angiotensin II receptor blockers; ARBs) is superior to other pharmacological therapy, and should be initiated as first-line treatment. Most of the calcium channel antagonists have been found to increase or to have no effect on microalbuminuria despite blood pressure reduction. Moreover, there is substantial controversy as to whether they may be associated with increased cardiovascular morbidity. Non-dihydropyridine derivatives and calcium channel antagonists, such as nitrendipine, may be nephroprotective and have favourable effects on patients outcomes. A renoprotective action of diuretics may be confined to indapamide. Although beta-adrenoreceptor blockers are effective antihypertensive agents, they may not adequately preserve kidney function in older diabetic patients. However, as add-on treatment to ACE inhibitors or ARBs, they are particularly beneficial in nephropathic patients at risk of cardiovascular disease or with arrhythmias, in whom they may prove life-saving.

Statin therapy for the treatment of diabetic dyslipidemia

The increasing prevalence of type 2 diabetes is a major problem for healthcare providers globally, since it is associated with serious microvascular and macrovascular complications. Although microvascular complications can be largely reduced with strict glycemic control, prevention of macrovascular disease involves a multifaceted approach that addresses all major risk factors, including dyslipidemia, hypertension, and insulin insensitivity. In particular, the treatment of diabetic dyslipidemia is a major challenge for diabetologists and cardiologists, as it is characterized by an array of lipid abnormalities. The management of diabetic dyslipidemia should initially include lifestyle approaches such as improved nutrition and weight reduction; however, the majority of patients require the addition of pharmacotherapy. Whilst insulin and/or oral hypoglycemic drugs are generally prescribed for the treatment of hyperglycemia, the addition of lipid-lowering drugs may be necessary for the control of diabetic dyslipidemia. The American Diabetes Association guidelines recommend lowering of low-density lipoprotein cholesterol (LDL-C) as a first priority. Hydroxy-methylglutaryl coenzyme A reductase inhibitors (statins) are recommended for first-line therapy in diabetic patients, since these agents are effective at reducing LDL-C levels. Whilst statins provide effective control of dyslipidemia in the majority of patients, more efficacious treatment regimens would provide greater benefit to more patients. Combination therapies may provide one solution to obtaining maximal lipid profile modifications, although the introduction of new, more efficacious agents for use as monotherapy may provide a more acceptable option, as drug combinations are often associated with poor tolerability and patient compliance.

Effect of ergotamine on plasma metabolite and insulin-like growth factor-1 concentrations in cows

Bovine plasma was assayed to determine if ergotamine affected plasma metabolite and insulin-like growth factor-1 (IGF-1) concentrations. In Experiment 1, four cows received a single bolus intravenous injection of ergotamine tartrate (19 microg/kg body wt.) or saline vehicle in a crossover design 2 days after prostaglandin-induced luteolysis. Treatmentxtime affected plasma glucose, triglyceride, total cholesterol and IGF-1 concentrations. Glucose and cholesterol were increased after ergotamine. Triglycerides were elevated within 1 h after ergotamine, but were decreased 3 h after ergotamine treatment. Plasma IGF-1 decreased in response to ergotamine. Blood constituents were unchanged after treatment with saline. In Experiment 2, six cows received a single bolus intravenous injection of ergotamine (20 microg/kg body wt.) or saline vehicle in a crossover design 10 days after receiving norgestomet (6 mg) via subcutaneous ear implant. Treatmentxtime affected glucose, triglycerides, total cholesterol and IGF-1 concentrations. Glucose and cholesterol were increased after ergotamine. Triglycerides were elevated 1 h after ergotamine and decreased 3-7 h after ergotamine. Plasma IGF-1 decreased after ergotamine treatment. Blood constituents were unresponsive to the saline vehicle. Results indicated ergotamine altered plasma metabolite and IGF-1 concentrations in cows.

Smoking diminishes the beneficial effect of statins: observations from the landmark trials

The landmark statin trials showed a significant reduction in morbidity and mortality associated with ischemic heart disease. However, it may not be widely appreciated that smoking had a marked adverse effect on outcome in these trials. In both the primary and secondary prevention setting, the effect of smoking was broadly similar. Smoking markedly increased the risk of events in the placebo and treatment groups. For example, in the primary prevention trials, this risk was 74-86% higher when smokers were compared with nonsmokers in the placebo groups. The corresponding figures for the secondary prevention trials were 23-61%. The risk of events in untreated nonsmokers was of a similar order to that seen in smokers taking statins. Although statin treatment was associated with a significant reduction in events in smokers, the best outcome was observed in nonsmokers treated with statins (primary prevention: lovastatin or pravastatin; secondary prevention: pravastatin or simvastatin). The highest risk of events in any group was in the smokers on placebo. This information may increase clinician and patient awareness as to the marked harmful effect of smoking relative to effective, evidence-based treatment (ie, the use of statins).