The metabolic syndrome phenotype is associated with raised circulating Big endothelin-1 independently of coronary artery disease in type 2 diabetes

The atherogenic dyslipidemia ratio [log(TG)/HDL-C] is associated with residual vascular risk, beta-cell function loss and microangiopathy in type 2 diabetes females

Background

Atherogenic dyslipidemia (AD), defined as low HDL-C plus elevated triglycerides (TG), comorbid to T2DM, increases cardiometabolic risk for CAD even when LDL-C is at target. In T2DM males, AD was shown to correlate with β-cell function loss, yet it is not established whether this applies across gender.

Aim

To establish the prevalence and severity of AD in T2DM females, and to determine how it relates to cardiometabolic phenotype, glucose homeostasis, micro- and macrovascular complications, and 10-year absolute CV risk (UKPDS Risk Engine).

Methods

340 T2DM females were ranked according to quintiles (Q) of the continuous variable log(TG)/HDL-C, with AD prevalence defined as HDL-C <50 mg.dL^-1 plus TG ≥150 mg.dL^-1, and β-cell function assessed with HOMA.

Results

AD prevalence was 35%; mean HDL-C and TG were 52 (15) and 160 (105) mg.dL^-1. AD was significantly related to central fat, metabolic syndrome, sedentarity and skeletal sarcopenia, as well as to _hsCRP, fibrinogen, uric acid, cystatin-C, Big ET-1, and 10-year UKPDS CV risk. AD correlated stepwise with lower β-cell function and hyperbolic product, and with accelerated loss of residual insulin secretion, higher HbA_1c and prevalent microangiopathy.

Conclusions

log(TG)/HDL-C is a simple means to grade AD and residual macrovascular risk in T2DM females. This ratio associates with major non-LDL cardiometabolic variables and ranks predicted CAD risk. In addition, log(TG)/HDL-C identifies worsening glucose homeostasis, poorer glycemic control, and prevalent microangiopathy.

eNOS [Glu298Asp] polymorphism, erectile function and ocular pressure in type 2 diabetes

BACKGROUND

  Imbalance in nitric oxide (NO), an atheroprotective vasodilator, is associated with endothelial dysfunction, cardiovascular diseases (CVD) and diabetic complications. Various endothelial NO synthase (eNOS) polymorphisms may affect NO bioavailability, thereby promoting adverse cardiovascular milieu.

MATERIALS AND METHODS

  To analyze glucose homeostasis, cardiometabolic phenotype, and micro- and macroangiopathies associated with eNOS G894T gene polymorphism in type 2 diabetes (T2DM). 210 T2DM outpatients (mean age (1SD) 70 (12); diabetes duration 19 (9) years; males:females 64:36%; metabolic syndrome 87%) had insulin sensitivity and b-cell function modelled with HOMA, alongside routine laboratory and endothelin measurements.

RESULTS

  GG, GT and TT genotypes represented 48% (n = 100), 39% (n = 83) and 13% (n = 27). Overall microangiopathy (retinopathy, neuropathy and/or nephropathy) was present in 74%, and overall macroangiopathy (CAD, PAD and/or TIA/stroke) in 45%. The TT genotype did not translate into a more severe vascular phenotype, as TT patients carrying the proposed risk genotype did not suffer a higher rate of micro- and macrovascular complications. On the other hand, erectile dysfunction, present in 60% of males (n = 135), was much more prevalent in TT males: 57% [GG & GT] vs. 93% in TT (p 0.0088). Ocular hypertension/glaucoma frequency (18% of the whole group) was also markedly different, albeit in opposing directions, between eNOS G894T gene polymorphism subgroups: 21% [GG & GT] vs. 0% prevalence (TT; p 0.0057).

CONCLUSIONS

  eNOS G894T gene polymorphism in homozygous TT carriers translates into opposing effects on erectile function (detrimental) and ocular hypertension/glaucoma (protective) in T2DM, without affecting glucose homeostasis determinants or the presence of micro- and macrovascular complications.

The multi-faceted outcomes of conjunct diabetes and cardiovascular familial history in type 2 diabetes

BACKGROUND

Familial history of early-onset CHD (EOCHD) is a major risk factor for CHD. Familial diabetes history (FDH) impacts β-cell function. Some transmissible, accretional gradient of CHD risk may exist when diabetes and EOCHD familial histories combine. We investigated whether the impact of such combination is neutral, additive, or potentiating in T2DM descendants, as regards cardiometabolic phenotype, glucose homeostasis and micro-/macroangiopathies.

METHODS

Cross-sectional retrospective cohort study of 796 T2DM divided according to presence (Diab[+]) or absence (Diab[-]) of 1st-degree diabetes familial history and/or EOCHD (CVD(+) and (-)). Four subgroups: (i) [Diab(-)CVD(-)] (n=355); (ii) [Diab(+)CVD(-)] (n=338); (iii) [Diab(-)CVD(+)] (n=47); and (iv) [Diab(+)CVD(+)] (n=56).

RESULTS

No interaction on subgroup distribution between presence of both familial histories, the combination of which translated into additive detrimental outcomes and higher rates of fat mass, sarcopenia, (hs)CRP and retinopathy. FDH(+) had lower insulinemia, insulin secretion, hyperbolic product, and accelerated hyperbolic product loss. An EOCHD family history affected neither insulin secretion nor sensitivity. There were significant differences regarding macroangiopathy/CAD, more prevalent in [Diab(-)CVD(+)] and [Diab(+)CVD(+)]. Among CVD(+), the highest macroangiopathy prevalence was observed in [Diab(-)CVD(+)], who had 66% macroangiopathy, and 57% CAD, rates higher (absolute-relative) by 23%-53% (overall) and 21%-58% (CAD) than [Diab(+)CVD(+)], who inherited the direst cardiometabolic familial history (p 0.0288 and 0.0310).

CONCLUSIONS

A parental history for diabetes markedly affects residual insulin secretion and secretory loss rate in T2DM offspring without worsening insulin resistance. It paradoxically translated into lower macroangiopathy with concurrent familial EOCHD. Conjunct diabetes and CV familial histories generate multi-faceted vascular outcomes in offspring, including lesser macroangiopathy/CAD.

Erectile dysfunction, microangiopathy and UKPDS risk in type 2 diabetes

BACKGROUND

Erectile dysfunction (ED) is a frequent comorbidity in patients with type 2 diabetes mellitus (T2DM), and is now increasingly considered a surrogate marker of endothelial dysfunction as well as a sentinel predictor of new-onset macroangiopathic events. Less attention, however, has been directed at the potential association of ED and microangiopathy in hyperglycaemic states.

METHODS

We analyzed 221 consecutive male T2DM outpatients in whom ED was assessed by the International Index of Erectile Function (IIEF-5) questionnaire. ED(+) patients (IIEF-5 1-20; n=83) were compared with an age-matched ED(-) cohort (IIEF-5 21-25; n=51), with similar diabetes duration, in terms of cardiovascular (CV) risk factors, micro-/macroangiopathy and the United Kingdom Prospective Diabetes Study (UKPDS) risk score.

RESULTS

Mean age and diabetes duration were 58 and 10 years, respectively. IIEF-5 score (1 S.D) was 23 (1) in ED(-) vs 11 (6) in ED(+). Anamnestic impotence and erectogenic drug use were reported by 52% and 36%, respectively, of ED(+) vs 12% and 8%, respectively, of ED(-) (P<0.0002 and P<0.0001, respectively). The metabolic syndrome prevalence (88% vs 64%; P=0.002) and central adiposity markers (waist, waist/height and visceral fat) were all significantly higher in ED(+). HbA(1c) was similar in both groups: 7.5% (1.3%), and there were also no significant differences in smoking, blood pressure, HOMA insulin sensitivity, cholesterol and glomerular filtration rate. However, prevalences of retinopathy, polyneuropathy and elevated albuminuria, and the composite endpoint of peripheral artery disease, transient ischaemic attacks and/or stroke, were markedly increased in ED(+) (all P<0.05). No differences were observed in coronary artery disease prevalence or in the UKPDS 10-year CV risk between the two ED groups.

CONCLUSION

IIEF-5-defined ED in men with T2DM is associated with a marked increase in the metabolic syndrome, central adiposity and microangiopathy. These data suggest that diagnosing ED in T2DM warrants detailed screening and monitoring for microangiopathy in target organs.

Raised natriuretic peptides, big-endothelin-1 and improved beta-cell function in type 2 diabetic males with hyperuricaemia

Urate, a naturally-occurring antioxidant, is a marker/factor for cardiovascular disease. Hyperuricaemia is associated with IR, MetS and endothelial dysfunction. We characterised the associations between neurohormones, uricaemia, and glucose homeostasis in type 2 diabetes mellitus (T2DM) males. Cross-sectional; 705 T2DM males divided into two groups: uric acid < 7.0 mg/dl (normouricaemic; n=476) versus uric acid >or= 7.0 mg/dl (hyperuricaemic; n=229). HOMA beta-cell function (B), insulin sensitivity (S), hyperbolic product (BxS), and (BxS) loss rate were determined alongside neurohormones (Nt-proANP, BNP, Big ET-1 and UII). Mean age and diabetes duration were not different between groups. Hyperuricaemics had more macroangiopathy, total/central adiposity, IR, hypertension, dyslipidemia and MetS prevalence. Nt-proANP and BNP levels were more than twice as high in hyperuricaemics, whereas Big ET-1 and UII were higher by 46% and 14%, respectively. HOMA (BxS) was higher in hyperuricaemics: 31 (16)% vs. 26 (18)% (p=0.0004). BxS loss rate was faster in normouricaemics: 1.36 (0.54)% vs. 1.20 (0.43)%/year(-1) (p<0.0001 ). The proportion with HbA(1C) < 7.0% was 39% (normouricaemics) vs. 49% (hyperuricaemics; p=0.0091). In T2DM males, hyperuricaemia is associated with raised neurohormones together with better beta-cell indices. Urate's dual properties may translate into beneficial (glucose homeostasis) and detrimental (raised neurohormones) effects.