Is microalbuminuria an integrated risk marker for cardiovascular disease and insulin resistance in both men and women?

Sex difference in the association between pathological albuminuria and subclinical atherosclerosis: insights from the I-Lan longitudinal aging study

Background: Pathological albuminuria (PAU) (urinary albumin creatinine ratio [UACR] ≥30 mg/g) is an independent risk factor of cardiovascular disease. PAU is more prevalent in men than women. We aimed to compare the association of PAU and the early phase of subclinical atherosclerosis (SA) between sexes.

Methods: 1228 subjects aged 50–90 years were stratified by sex and UACR (normal or PAU). SA was defined as mean carotid intima-media thickness ≥75th percentile of the cohort. Demographics and SA prevalence were compared between groups. Multivariate logistic regression was performed to assess the relationship between PAU and SA.

Results: Both men and women with PAU had increased prevalence of hypertension, anti-hypertensive therapy, and metabolic syndrome than controls. Men with PAU were older and had greater waist circumference and total body fat percentage. Sex disparity was observed in associations between waist-to-height ratio, total body fat, and UACR. After adjusting for traditional risk factors, multivariate logistic regression disclosed that PAU was independently associated with SA in men (adjusted odds ratio 1.867, 95% CI 1.066–3.210) but not in women.

Conclusion: The relationship of PAU and SA differed between sexes. This result may highlight the need for sex-specific risk management strategies to prevent atherosclerosis.

A Higher Fructose Intake Is Associated with Greater Albuminuria in Subjects with Type 2 Diabetes Mellitus

The aim of this single center cross-sectional study was to investigate the association between fructose intake and albuminuria in subjects with type 2 diabetes mellitus (T2DM). This is a single center cross-sectional study. One hundred and forty-three subjects with T2DM were recruited from the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. The median daily fructose intake was estimated with a prospective food registry during 3 days (2 week-days and one weekend day) and they were divided into low fructose intake (<25 g/day) and high fructose intake (≥ 25 g/day). Complete clinical and biochemical evaluations were performed, including anthropometric variables and a 24-hour urine collection for albuminuria determination. One hundred and thirty-six subjects were analyzed in this study. We found a positive significant association between daily fructose intake and albuminuria (ρ= 0.178, p=0.038) in subjects with type 2 diabetes mellitus. Other variables significantly associated with albuminuria were body mass index (BMI) (ρ= 0.170, p=0.048), mean arterial pressure (MAP) (ρ= 0.280, p=0.001), glycated hemoglobin (A1c) (ρ= 0.197, p=0.022), and triglycerides (ρ= 0.219, p=0.010). After adjustment for confounding variables we found a significant and independent association between fructose intake and albuminuria (β= 13.96, p=0.006). We found a statistically significant higher albuminuria (60.8 [12.8-228.5] versus 232.2 [27.2-1273.0] mg/day, p 0.002), glycated hemoglobin (8.6±1.61 versus 9.6±2.1 %), p= 0.003, and uric acid (6.27±1.8 versus 7.2±1.5 mg/dL), p=0.012, in the group of high fructose intake versus the group with low fructose intake, and a statistically significant lower creatinine clearance (76.5±30.98 mL/min versus 94.9±36.8, p=0.014) in the group with high fructose intake versus the group with low fructose intake. In summary we found that a higher fructose intake is associated with greater albuminuria in subjects with T2DM.

A multicenter cohort study of primary hypertension in Korea: study design and interim analysis of the Korean registry of target organ damage in hypertension (KorHR)

BACKGROUND

The Korean Registry of Target Organ Damage in Hypertension aims to evaluate the clinical characteristics and prevalence of subclinical target organ damage in Korean hypertensive patients.

METHOD

This is a prospective, observational, multicenter cohort study in which 23 university hospitals participated. Since May 2013, we have enrolled 1,318 consecutive hypertensive patients without known cardiovascular disease who met the following inclusion criteria: 1) age older than 30 years and 2) the first visit to the participating hospitals was within the last 5 years.

RESULTS

The mean age was 52 ± 12 years; 62.1% were male, and 41.3% were incident hypertensives. Patients with diabetes mellitus accounted for 7.8% of the population and 43.8% had hyperlipidemia or were on statins at baseline. The mean office blood pressures were 152 ± 20/96 ± 14 mmHg for incident hypertensive patients and 129 ± 13/78 ± 10 mmHg for patients on treatment. Patients with electrocardiographic and echocardiographic left ventricular hypertrophy accounted for 18.9 and 25.6%, respectively. The mean brachial-ankle pulse wave velocity (PWV) was 1564 ± 293 m/s and 19.5% had PWV values of more than 1750 cm/s. Patients with microalbuminuria and chronic kidney disease accounted for 21 and 4%, respectively. The first prescribed class of antihypertensive medications was angiotensin converting enzyme inhibitors in 2.9%, angiotensin receptor blockers (ARBs) in 57.5%, diuretics in 7.6%, calcium channel blockers (CCBs) in 61.0%, beta blockers in 17.3%, and fixed dose combination pill in 27.8%.

CONCLUSION

Our interim analysis shows that subclinical target organ damage in hypertension is considerably present for incident or treated hypertensive patients. CCBs and ARBs were the most commonly prescribed classes of antihypertensive medications and fixed dose combination pills were actively used in Korea.

TRIAL REGISTRATION

NCT01861080. Registered 16 May 2013.

Association of insulin resistance with chronic kidney disease in non-diabetic subjects with normal weight

OBJECTIVE

To the best of our knowledge, the association of insulin resistance (IR) with chronic kidney disease (CKD) has not been well studied in normal-weight individuals. The aim of this study is to examine whether IR is associated with CKD in non-diabetic subjects with normal weight. We also examine whether the presence of obesity modifies the association of IR with CKD.

METHODS

Data were drawn from a cross-sectional survey in China. Both estimated glomerular filtration rate and urinary albumin to creatinine ratio were used as markers of CKD. Logistic regression models and the quartiles of homeostatic model assessment of insulin resistance were used to explore the associations of IR with CKD in entire cohort, normal-weight and overweight/obese subpopulations.

RESULTS

In normal-weight subpopulation, the prevalence of IR and metabolic syndrome were 11.11% and 8.99%, respectively. In the entire cohort, the highest quartile HOMA-insulin resistance had a 70% increased risk for CKD (RR 1.70, 95% CI 1.07, 2.71, P=0.03, comparing the highest to the lowest quartile). However, when adding obesity to the model, the association was abolished. IR was associated with CKD in overweight/obese subpopulation but not in normal-weight subpopulation.

CONCLUSION

IR and MetS in normal-weight individuals is common in the Chinese population. IR is associated with CKD in overweight/obese subpopulation but not in normal-weight subpopulation and the presence of obesity modifies the association of IR with CKD.

Endothelial function and urine albumin levels among asymptomatic Mexican-Americans and non-Hispanic whites

Background-

Mexican-Americans (MA) exhibit increases in various cardiovascular disease (CVD) risk factors compared to non-Hispanic Whites (NHW), yet are reported to have lower CVD mortality rates. Our aim was to help explain this apparent paradox by evaluating endothelial function and urine albumin levels in MA and NHW.

Methods-

One hundred-five MA and 100 NHW adults were studied by brachial artery flow-mediated dilatation (FMD), blood and urine tests. Participants were studied by ultrasound-determined brachial artery flow-mediated dilatation (FMD), blood and urine tests, at a single visit.

Results-

Despite higher BMI and triglycerides in MA, MA demonstrated higher FMD than did NHW (9.1 ± 7.3% vs. 7.1 ± 6.3%, p < 0.04). Among MA, urinary albumin was consistently lower in participants with FMD ≥ 7% FMD versus < 7% FMD (p < 0.006). In multivariate analyses in MA men, urinary albumin was inversely related to FMD (r = -0.26, p < 0.05), as were BMI and systolic blood pressure. In MA women, urinary albumin:creatinine ratio was an independent inverse predictor of FMD (p < 0.05 ).

Conclusion-

To our knowledge, this is the first study to analyze, in asymptomatic adults, the relation of MA and NHW ethnicity to FMD and urine albumin levels. The findings confirm ethnic differences in these important subclinical CVD measures.

Early pulse pressure and low-grade proteinuria as independent long-term risk factors for new-onset diabetes mellitus after kidney transplantation

Risk factors for new-onset diabetes after transplantation (NODAT) need to be assessed in large cohorts. We retrospectively evaluated the impact of early (3 and 6 months after transplantation) proteinuria, urinary albumin excretion (UAE) and arterial pressure on NODAT in 828 Caucasian renal transplant recipients (median follow-up: 5.3 years; 5832 patient-years). The 10- and 20-year incidence of NODAT was 15.0% and 22.0%, respectively. Low-grade (<1 g/day) (HR: 2.04 [1.25-3.33], p = 0.0042) and very low-grade (<0.3 g/day) (HR: 2.21 [1.32-3.70], p = 0.0025) proteinuria were independent risk factors for NODAT. There was a dose-dependent relationship across UAE categories (increasing risk from normoalbuminuria to macroalbuminuria) with NODAT. Tacrolimus, sirolimus and beta-blockers (HR: 1.86 [1.07-3.22], p = 0.0277) were significantly associated with NODAT even after multiple adjustments, but not diuretics, angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers. Systolic arterial pressure (HR per 10 mmHg: 1.16 [1.03-1.29], p = 0.0126) and pulse pressure (HR: 1.26 [1.12-1.43], p = 0.0002) were associated with NODAT. Only pulse pressure remained significant after adjustments. Patients at highest risks had early proteinuria and pulse pressure >60 mmHg. Early low-grade proteinuria and pulse pressure (in addition to beta-blockers) constitute independent risk factors for NODAT; they may be markers of the metabolic syndrome and/or vascular damage in renal transplant recipients.

Predictors of acute myocardial infarction mortality in hypertensive patients treated in primary care: a population-based follow-up study in the Skaraborg Project

OBJECTIVE

To explore risk factors for acute myocardial infarction (AMI) mortality in hypertensive patients treated in primary care.

DESIGN

Community-based cohort study.

SETTING

Hypertension outpatient clinic in primary health care.

SUBJECTS

Patients who consecutively underwent an annual follow-up during 1992-1993 (n =894; 377 men and 517 women).

METHODS

All events of fatal AMI were ascertained by record linkage to the National Mortality Register to December 31, 2002. Gender-specific predictors for AMI mortality were analysed by Cox regression.

MAIN OUTCOME MEASURE

AMI mortality.

RESULTS

During a mean follow-up of 8.7 years 32 cases (8.5%) of fatal AMI were observed in men and 31 cases (6.0%) were observed in women. Most important predictors for AMI mortality in men were microalbuminuria (HR 3.8, CI 1.8-8.0) and left ventricular hypertrophy (HR 4.0, CI 1.7-9.4), whilst in women type 2 diabetes (HR 4.8, CI 2.4-9.8) was an important predictor. In hypertensive patients without diabetes male gender was associated with high AMI mortality (HR 2.7, CI 1.4-5.3), but in patients with both hypertension and type 2 diabetes the higher risk in men disappeared (HR 0.8, CI 0.4-1.7).

CONCLUSION

Cardiovascular disease risk factors remain strong predictors of AMI mortality in hypertensive patients but with a different pattern in the two genders. Markers of organ damage are more important predictors in men, whereas markers of impaired glucose metabolism are more important predictors in women.

Endothelial dysfunction and cardiovascular risk profile in long-term withdrawing alcoholics

BACKGROUND

Rates of cardiovascular morbidity and mortality are greater in heavy alcoholics than in either teetotallers or light-to-moderate drinkers.

OBJECTIVE

On the assumption that factors leading to atherosclerotic damage remain operative even after long-term alcohol withdrawal, we studied the possible mechanisms of raised cardiovascular risk in former heavy alcoholics.

METHODS

Forty-two apparently disease-free, normotensive alcoholics detoxified for 37.1 +/- 31.9 (SD) months, median 24, participated in the study. They were compared with 39 lifetime alcohol-abstaining control subjects, carefully matched for age, sex, body mass index, smoking and dietary habits, physical activity, lipids and fasting glucose. Endothelial function (flow-mediated dilation of brachial artery, high-resolution ultrasound technique), blood pressure, and some parameters of endothelial activation, oxidative stress, vascular inflammation and insulin sensitivity were measured.

RESULTS

The maximal percentage of flow-mediated dilatation was reduced in detoxified alcoholics (10.1 +/- 4.6 versus 14.9 +/- 7.4, P < 0.001) who also showed significantly higher blood pressure (systolic 127.5 +/- 12.9 versus 118.2 +/- 10.7 mmHg, P < 0.001; diastolic 79.4 +/- 7.1 versus 74.6 +/- 6.4 mmHg, P < 0.01; mean 95.4 +/- 8.2 versus 89.1 +/- 7.3 mmHg, P < 0.001), uric acid (5.0 +/- 1.1 versus 4.4 +/- 0.8 mg/dl, P < 0.05), high-sensitivity C-reactive protein (2.1 +/- 2.0 versus 1.0 +/- 0.9 mg/l, P < 0.01), endothelin-1 (0.38 +/- 0.11 versus 0.17 +/- 0.10 pg/ml, P < 0.001) and fasting insulin (10.4 +/- 4.5 versus 5.6 +/- 1.6 muU/ml, P < 0.001) with abnormal homeostasis model assessment index of insulin resistance (2.3 +/- 1.1 versus 1.2 +/- 0.4, P < 0.001).

CONCLUSION

Previous heavy alcoholism, in spite of long-term withdrawal, is associated with endothelial dysfunction and a wide cluster of haemodynamic, vascular and metabolic abnormalities that indicate an unfavourable cardiovascular and metabolic risk profile even in apparently disease-free former alcoholics.

Waist circumference and the metabolic syndrome predict the development of elevated albuminuria in non-diabetic subjects: the DESIR Study

OBJECTIVE

Metabolic determinants of microalbuminuria remain poorly understood in non-diabetic individuals and particularly in women. We investigated in both sexes whether an elevated waist circumference (WC) or the presence of the metabolic syndrome (MetS) predict the development of elevated albuminuria at 6 years.

DESIGN AND PATIENTS

We studied 2738 subjects from the DESIR cohort without microalbuminuria or diabetes at baseline and who were followed up for 6 years.

RESULTS

At 6 years, 254 individuals [9.3%; 95% confidence interval (CI) 8.2-10.4%] had developed elevated albuminuria (> or = 20 mg/l), which was significantly and positively associated with WC and blood pressure, but not with fasting glucose, lipids or body mass index in either sex. In both sexes, subjects with a high WC or with MetS at baseline were more likely to develop elevated albuminuria at 6 years compared with those with a normal WC or absence of MetS. In multivariate logistic analysis, WC as a continuous variable or a WC of 94 cm or greater for men and a WC greater than 88 cm for women were predictive of the development of elevated albuminuria, after adjusting for age, hypertension, the use of angiotensin-converting enzyme inhibitors, fibrinogen and glycaemia. MetS was a risk factor for elevated albuminuria in men (odds ratio 1.87; 95% CI 1.25-2.81), with differences according to the MetS definition.

CONCLUSION

Abdominal adiposity is related to the development of elevated albuminuria in both sexes, suggesting that the measurement of WC may improve the identification of non-diabetic individuals at risk of developing microalbuminuria and emphasizing the interest of screening for albuminuria among those with MetS.

Increased urinary albumin excretion, insulin resistance, and related cardiovascular risk factors in patients with type 2 diabetes: evidence of a sex-specific association

OBJECTIVE

While the relevant role of insulin resistance in the pathogenesis of increased urinary albumin excretion (UAE) is well established in type 1 diabetes, its contribution in type 2 diabetes is controversial. Our aim was to investigate whether insulin resistance was associated with increased UAE in a large cohort of patients with type 2 diabetes.

RESEARCH DESIGN AND METHODS

A total of 363 men and 349 women, aged 61 +/- 9 years, with a disease duration of 11 +/- 9 years and HbA(1c) levels of 8.6 +/- 2.0% were included. Insulin resistance was derived from the homeostasis model assessment of insulin resistance (HOMA(IR)), and UAE was derived from the albumin-to-creatinine ratio (ACR) defined as increased if the value was > or =2.5 mg/mmol in men and > or =3.5 mg/mmol in women. ACR was correlated with HOMA(IR) (r = 0.15, P = 0.0001), independently of age, disease duration, blood pressure, HbA(1c), triglycerides, waist circumference, and smoking.

RESULTS

When the two sexes were investigated separately, a significant correlation between ACR and HOMA(IR) was reached in men (n = 363; r = 0.21, P = 0.0001) but not women (n = 349; r = 0.08, P = 0.14), suggesting that insulin resistance and sex may interact (P for interaction = 0.04) in determining UAE. When men were subgrouped into quartiles of HOMA(IR), those of the third and fourth quartile (i.e., the most insulin resistant) were at higher risk to have increased ACR than patients of the first quartile (third quartile: odds ratio 2.2 [95% CI 1.2-4.2], P = 0.01) (fourth quartile: 4.1 [2.2-7.9], P = 0.00002). Finally, ACR was significantly higher in men with two or more insulin resistance-related cardiovascular risk factors (i.e., abdominal obesity, dyslipidemia, and arterial hypertension) than in men with fewer than two insulin resistance-related cardiovascular risk factors (0.90 [0.2-115.1] vs. 1.56 [0.1-1367.6], respectively, P = 0.005).

CONCLUSIONS

In type 2 diabetic patients, increased UAE is strongly associated with insulin resistance and related cardiovascular risk factors. This association seems to be stronger in men than in women.

Microalbuminuria as a marker of cardiovascular and renal risk in type 2 diabetes mellitus: a temporal perspective

Microalbuminuria is a marker for diabetic nephropathy. It also signifies cardiovascular disease, as well as nephropathy, in type 2 diabetes (DM2). Microalbuminuria may precede DM2, occurring with the insulin resistance syndrome and its components, including obesity and hypertension. Other indicators of cardiovascular risk, such as markers of inflammation, are associated with microalbuminuria in populations of patients with and without diabetes. With the rising prevalence of DM2 in minority youth, especially in Native Americans, a marker for future disease risk would allow earlier prevention strategies to be tested. Before microalbuminuria can be used in a prevention strategy, more needs to be known about the mechanism(s) of the association between elevated excretion, its relationship to glucose intolerance, and its relative contribution to cardiovascular and renal disease. These questions are especially applicable as we begin to observe the long-term complications of diabetes in youth.

Microalbuminuria: marker of vascular dysfunction, risk factor for cardiovascular disease

Based on the data from large single and multi-center clinical trials, including the Heart Outcomes Prevention Evaluation (HOPE) study, it is clear that the presence of microalbuminuria is a signal from the kidney that cardiovascular risk is increased and that vascular responses are altered. This is exemplified by studies that have demonstrated that the compensatory vasodilation seen following relief from prolonged ischemia or infusion of vasodilators such as nitroglycerin is blunted in people with microalbuminuria. Thus, the presence of between 30 and 299 mg/day of albumin in the urine is associated with abnormal vascular responsiveness, which may be the result of more advanced atherosclerosis and not necessarily related to the presence of hypertension or renal disease. Agents known to reduce the rise in microalbuminuria or actually reduce the level of microalbuminuria, such as ACE inhibitors, angiotensin receptor blockers, HMG-CoA reductase inhibitors, beta blockers, non-dihydropyridine calcium channel blockers and diuretics, have all been shown to reduce cardiovascular mortality and in some cases preserve renal function. This article will present an overview of the data that support the assertion that a reduction in the rise of microalbuminuria is a significant consideration in the selection of agents to treat a given risk factor (cholesterol or blood pressure) to a recommended target goal. Achieving such a goal with agents that also impact microalbuminuria will provide for a more complete cardiovascular risk reduction.