Impact of metabolic syndrome and its severity on microvascular complications in type 2 diabetes

Fatty liver and atherogenic dyslipidemia have opposite effects on diabetic micro- and macrovascular disease

BACKGROUND AND AIMS

Non-alcoholic fatty liver (FL) is comorbid with obesity, metabolic syndrome and type 2 diabetes. Atherogenic dyslipidaemia (AD), frequent in FL, is associated with risk of micro- and macrovascular complications. Given the paradoxical ocular protection of FL in T2DM, we studied how FL modulates micro- and macrovascular complications as a function of AD.

METHODS

Cross-sectional factorial analysis of 744 diabetic patients in whom FL, identified by ultrasonography, was present in 68%. AD, defined by low HDL-C plus elevated TG, was present in 45%. Four groups were analysed as regards cardiometabolic features, micro-/macroangiopathies, cataract and ocular hypertonia: FL[-]AD[-] (n = 171); FL[-]AD[+] (n = 66); FL[+]AD[-] (n = 235); and FL[+]AD[+] (n = 272).

RESULTS

Age, gender and glycemic control were similar across groups. Prevalence of overall macroangiopathy and coronary artery disease were higher in patients with AD, irrespective of FL. Overall macroangiopathy was higher, by 64% in FL[-]AD[+] and by 38% in FL[+]AD[+]. Coronary artery disease was higher, by 128%, in FL[-]AD[+], and by 67%, in FL[+]AD[+]. (Micro)albuminuria was more frequent (+55%) in FL[-] AD[+] compared to FL[-] AD[-]. Retinopathy prevalence was 35% in FL[-], unaffected by AD. Retinopathy frequency was much lower in FL[+], irrespective of AD, decreased by -47% in FL[+]AD[-] and -32% in FL[+]AD[+] (vs. FL[-]AD[-]). Ocular hypertonia was present in 13%, and its prevalence was also markedly lower (-31%) in FL[+]. Cataract frequency was 29%, also lesser in FL[+] (24% vs. 39%), irrespective of AD.

CONCLUSIONS

Multi-level eye protection in diabetes is linked to non-alcoholic fatty liver independently of atherogenic dyslipidemia.

High rates of atherogenic dyslipidemia, β-cell function loss, and microangiopathy among Turkish migrants with T2DM

AIMS

Non-Caucasian migrants require dedicated approaches in diabetes management due to specific genetic; socio-cultural; demographic and anthropological determinants. Documenting such phenotypes allows for better understanding unmet needs and management priorities.

METHODS

This age- and sex-adjusted case-control (1:6 ratio) study compared 56 T2DM Turkish migrants (70% males) resident in Belgium [Tu] with 336 T2DM Caucasians [Ca], all benefiting from state-funded healthcare.

RESULTS

The 2 groups did not differ regarding BMI; waist circumference; fat mass; visceral fat; muscle mass; insulin sensitivity; insulinemia; metabolic syndrome; hypertension; lipid-modifying drugs; and macroangiopathy. They also had similar renal function and (micro)albuminuria. Education (low/high) and ethanol consumption were lower among [Tu]: 83/17% and 2.0 U/wk vs 43/57% and 13.6 U/wk in [Ca] (p < 0.0001). β-cell function loss (BCF) was higher in [Tu]: 1.58(0.45) vs 1.35(0.54)%/yr (p 0.0027), as was HbA1c: 8.39(1.91) vs 7.48(1.35)% in [Ca] (p < 0.0001). Diabetes duration and insulin use were increased in [Tu]: 19(9)yr and 70% vs 16(8)yr and 48% in [Ca] (p 0.0111 and 0.0024). Atherogenic dyslipidemia (AD) was more prevalent in [Tu]: 64% vs 49% (p 0.0309), who had higher non-HDL-C; apolipoprotein B₁₀₀; LDL-C; and triglycerides; and lower HDL-C and apolipoprotein A-I levels (all p < 0.05). Overall microangiopathy; retinopathy; and neuropathy were more prevalent in [Tu]: 55-35-37% vs 40-18-20% in [Ca] (all p < 0.05).

CONCLUSIONS

These results should raise concerns about poor glycaemic control; rapid BCF loss; severe AD; and microangiopathy among Turkish migrants with T2DM. Targeting AD could improve the cardiometabolic profile of this minority given the relationship between AD and residual vascular risk.

[HDL-C/apoA-I]: A multivessel cardiometabolic risk marker in women with T2DM

AIMS

Although women have higher high-density lipoprotein cholesterol (HDL-C) than have men, their HDL particles are also prone to become small, dense, and dysfunctional in case of type 2 diabetes mellitus (T2DM). To assess the vascular risk related to HDLs of different sizes/densities without direct measurement, we adjusted HDL-C to its main apolipoprotein (apoA-I) as [HDL-C/apoA-I]. This ratio estimates HDL sizes and provides indices as to their number, cholesterol load, and density.

METHODS

We stratified 280 Caucasian T2DM women according to [HDL-C/apoA-I] quartiles (Q) to determine how they are segregated according to cardiometabolic risk, β-cell function, glycaemic control, and vascular complications. Five parameters were derived from combined determination of HDL-C and apoA-I: HDL size, HDL number, cholesterol load per particle (pP), apoA-I pP, and HDL density.

RESULTS

An adverse cardiometabolic profile characterized QI and QII patients whose HDLs were denser and depleted in apoA-I, whereas QIII patients had HDLs with characteristics closer to those of controls. QIV patients had HDLs of supernormal size/composition and a more favourable phenotype in terms of fat distribution; insulin sensitivity (64% vs 41%), metabolic syndrome, and β-cell function (32% vs 23%); exogenous insulin (44 vs 89 U·d^-1 ); and glycaemic control (glycated haemoglobin, 56 vs 61 mmol·mol^-1 ), associated with lower prevalence of microvascular/macrovascular complications: all-cause microangiopathy 47% vs 61%; retinopathy 22% vs 34%; all-cause macroangiopathy 19% vs 31%; and coronary artery disease 6% vs 24% (P < .05).

CONCLUSION

[HDL-C/apoA-I] can stratify T2DM women according to metabolic phenotype, macrovascular and coronary damage, β-cell function, microangiopathic risk, and retinopathy. This ratio is a versatile and readily available marker of cardiometabolic status and vascular complications in T2DM women.

Size, density and cholesterol load of HDL predict microangiopathy, coronary artery disease and β-cell function in men with T2DM

The role of high-density lipoprotein cholesterol (HDL-C) as modifiable risk factor for cardiovascular (CV) disease is increasingly debated, notwithstanding the finding that small-dense and dysfunctional HDL are associated with the metabolic syndrome and T2DM. In order to better clarify the epidemiological risk related to HDL of different size/density, without resorting to direct measures, it would seem appropriate to adjust HDL-C to the level of its main apolipoprotein (apoA-I), thereby providing an [HDL-C/apoA-I] ratio. The latter allows not only to estimate an average size for HDLs, but also to derive indices on particle number, cholesterol load, and density. So far, the potential usefulness of this ratio in diabetes is barely addressed. To this end, we sorted 488 male patients with T2DM according to [HDL-C/apoA-I] quartiles (Q), to determine how the ratio relates to cardiometabolic risk, β-cell function, glycaemic control, and micro- and macrovascular complications. Five lipid parameters were derived from the combined determination of HDL-C and apoA-I, namely HDL size; particle number; cholesterol load/particle; apoA-I/particle; and particle density. An unfavorable cardiometabolic profile characterized patients from QI and QII, in which HDLs were pro-atherogenic, denser and apoA-I-depleted. By contrast, QIII patients had an [HDL-C/apoA-I] ratio close to that of non-diabetic controls. QIV patients had better than average HDL size and composition, and in those patients whose [HDL-C/apoA-I] ratio was above normal, a more favorable phenotype was observed regarding lifestyle, anthropometry, metabolic comorbidities, insulin sensitivity, MetS score/severity, glycaemic control, and target-organ damage pregalence in small or large vessels. In conclusion, [HDL-C/apoA-I] and the resulting indices of HDL composition and functionality predict macrovascular risk and β-cell function decline, as well as overall microangiopathic risk, suggesting that this ratio could serve both in cardiometabolic assessment and as biomarker of vascular complications.

The normal-weight type 2 diabetes phenotype revisited

BACKGROUND

Type 2 diabetes (T2DM) is associated with obesity, insulin resistance and the metabolic syndrome (MetS). In non-diabetic populations, features of metabolic obesity (MO) are observed in a minority of normal-weight (NW) subjects. The cardiometabolic status of metabolically obese but normal-weight (MONW) individuals has not yet been phenotyped in T2DM.

PATIENTS AND METHODS

Prevalence and features of MONW were analyzed in 1244 T2DM patients, in whom MONW was identified as a BMI <25.0 and a MetS score ≥3/5. Among NW (n=262; 21%), those without MetS (n=152; NW-MetS[-]) were compared to NW-MetS[+] (n=110; i.e. 42% of NW and 9% of all T2DM).

RESULTS

There were no differences between groups in age; gender; diabetes duration; smoking; BP; and LDL-C. NW-MetS[+] had higher BMI; waist; fat mass; visceral fat; liver steatosis and HbA1c, and lower insulin sensitivity. Non-right-handedness was twice-higher (18%) in NW-MetS[-]. NW-MetS[+] had higher apoB100 and triglycerides, and lower HDL-C and LDL size. Macroangiopathy was present in 39% of NW-MetS[+] vs. 22% of NW-MetS[-], as coronary (23% vs. 14%) or peripheral artery disease (14% vs. 5%) and TIA/stroke (15% vs. 7%). Microangiopathy was present in 54% of NW-MetS[+] vs. 32% of NW-MetS[-], as retinopathy (25% vs. 13%); neuropathy (29% vs. 18%); and albuminuria (39% vs. 20%).

CONCLUSIONS

MONW among T2DM represents a significant minority (about 1 in 10). Their cardiometabolic phenotype deserves attention due to multiple comorbidities, including a twice-higher prevalence of micro-/macrovascular damage in patients wrongly perceived at lower risk due to normal BMI. Unexpectedly, non-right-handedness was over-represented among metabolically healthy patients.

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.

Reducing vascular events risk in patients with dyslipidaemia: an update for clinicians

Reducing the risk of vascular events in patients with dyslipidaemia requires cardiovascular disease risk stratification and lifestyle/pharmacological intervention on modifiable risk factors. Reduction of low-density lipoprotein cholesterol (LDL-C) with statins is highly effective in reducing cardiovascular disease in patients with and without diabetes, but leaves unaddressed a sizeable residual vascular risk (RvR), which is rarely quantified in routine clinical practice. Such RvR may relate to lack of strict target attainment for all atherogenic variables [LDL-C, non-high-density lipoprotein cholesterol (HDL-C) and/or apolipoprotein B(100)]. Another substantial lipid-related and modifiable RvR component is related to atherogenic dyslipidaemia, especially as global rates of obesity, type 2 diabetes and metabolic syndrome are increasing. Atherogenic dyslipidaemia is associated with insulin-stimulated very-low-density lipoprotein overproduction and reduced reverse cholesterol transport. The hallmark of atherogenic dyslipidaemia is the coexistence of low HDL-C and elevated triglycerides. Therapeutic lifestyle changes and combination lipid-lowering therapy with drugs targeting atherogenic dyslipidaemia (such as fibrates or innovative drugs targeting atherogenic dyslipidaemia and/or apolipoprotein B(100) metabolism) on top of background statins, have a potential to reduce RvR in high-risk groups, as shown in the Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial, in which combination therapy with simvastatin plus fenofibrate decreased macrovascular risk in patients with diabetes and atherogenic dyslipidaemia, and retinopathy risk irrespective of baseline lipids.

Non-invited review: prevention of microvascular diabetic complications by fenofibrate: lessons from FIELD and ACCORD

Microvascular complications are common in type 2 diabetes in primary care. Intensified management of glycaemia or blood pressure had little effect on microvascular complication rates in recent large trials (ADVANCE, VADT, ACCORD). In 2005, the FIELD study demonstrated a significant reduction in the need for laser treatment for retinopathy, and of progression of renal dysfunction, with fenofibrate versus placebo. The FIELD ophthalmology sub-study showed that fenofibrate reduced the risk of new retinopathy and progression of retinopathy. Also, fenofibrate versus placebo significantly reduced the risk of non-traumatic, diabetes-related amputations in a post-hoc analysis from FIELD. Recently, the results of the ACCORD Lipid study were consistent with these findings, as fenofibrate significantly reduced progression of retinopathy and albuminuria, apparently independent of effects on lipids. These findings suggest a role for fenofibrate in the prevention of major diabetic microvascular complications.