The association between the food environment and adherence to healthy diet quality: the Maastricht Study

OBJECTIVE

The purpose of this study is to determine if healthier neighbourhood food environments are associated with healthier diet quality.

DESIGN

This was a cross-sectional study using linear regression models to analyse data from the Maastricht Study. Diet quality was assessed using data collected with a FFQ to calculate the Dutch Healthy Diet (DHD). A buffer zone encompassing a 1000 m radius was created around each participant home address. The Food Environment Healthiness Index (FEHI) was calculated using a Kernel density analysis within the buffers of available food outlets. The association between the FEHI and the DHD score was analysed and adjusted for socio-economic variables.

SETTING

The region of Maastricht including the surrounding food retailers in the Netherlands.

PARTICIPANTS

7367 subjects aged 40-75 years in the south of the Netherlands.

RESULTS

No relationship was identified between either the FEHI (B = 0·62; 95 % CI = -2·54, 3·78) or individual food outlets, such as fast food (B = -0·07; 95 % CI = -0·20, 0·07) and diet quality. Similar null findings using the FEHI were identified at the 500 m (B = 0·95; 95 % CI = -0·85, 2·75) and 1500 m (B = 1·57; 95 % CI = -3·30, 6·44) buffer. There was also no association between the food environment and individual items of the DHD including fruits, vegetables and sugar-sweetened beverages.

CONCLUSION

The food environment in the Maastricht area appeared marginally unhealthy, but the differences in the food environment were not related to the quality of food that participants reported as intake.

The Associations of Habitual Intake of Sulfur Amino Acids, Proteins and Diet Quality with Plasma Sulfur Amino Acid Concentrations: The Maastricht Study

BACKGROUND

Plasma sulfur amino acids (SAAs), i.e., methionine, total cysteine (tCys), total homocysteine (tHcy), cystathionine, total glutathione (tGSH), and taurine, are potential risk factors for obesity and cardiometabolic disorders. However, except for plasma tHcy, little is known about how dietary intake modifies plasma SAA concentrations.

OBJECTIVE

To investigate whether the intake of SAAs and proteins or diet quality is associated with plasma SAAs.

METHODS

Data from a cross-sectional subset of The Maastricht Study (n = 1145, 50.5% men, 61 interquartile range: [55, 66] y, 22.5% with prediabetes and 34.3% with type 2 diabetes) were investigated. Dietary intake was assessed using a validated food frequency questionnaire. The intake of SAAs (total, methionine, and cysteine) and proteins (total, animal, and plant) was estimated from the Dutch and Danish food composition tables. Diet quality was assessed using the Dutch Healthy Diet Index, the Mediterranean Diet Score, and the Dietary Approaches to Stop Hypertension score. Fasting plasma SAAs were measured by liquid chromatography (LC) tandem mass spectrometry (MS) (LC/MS-MS). Associations were investigated with multiple linear regressions with tertiles of dietary intake measures (main exposures) and z-standardized plasma SAAs (outcomes).

RESULTS

Intake of total SAAs and total proteins was positively associated with plasma tCys and cystathionine. Associations were stronger in women and in those with normal body weight. Higher intake of cysteine and plant proteins was associated with lower plasma tHcy and higher cystathionine. Higher methionine intake was associated with lower plasma tGSH, whereas cysteine intake was positively associated with tGSH. Higher intake of methionine and animal proteins was associated with higher plasma taurine. Better diet quality was consistently related to lower plasma tHcy concentrations, but it was not associated with the other SAAs.

CONCLUSION

Targeted dietary modifications might be effective in modifying plasma concentrations of tCys, tHcy, and cystathionine, which have been associated with obesity and cardiometabolic disorders.

Lower heart rate variability, an index of worse autonomic function, is associated with worse beta cell response to a glycemic load in vivo-The Maastricht Study

OBJECTIVE

We investigated, using population-based data, whether worse autonomic function, estimated from lower 24-hour heart rate variability (HRV), was associated with beta cell function, assessed from beta cell response during an oral glucose tolerance test (OGTT).

RESEARCH DESIGN AND METHODS

We used cross-sectional data from The Maastricht Study, a population-based cohort study (N = 2,007; age, mean ± SD:60 ± 8 years; 52% men; and 24% with type 2 diabetes). We used linear regression analyses with adjustment for potential confounders (demographic, cardiovascular, and lifestyle factors) to study the associations of time- and frequency-domain HRV (composite scores) with overall beta cell response (estimated from a composite score calculated from: C-peptidogenic index, overall insulin secretion, beta cell glucose sensitivity, beta cell potentiation factor, and beta cell rate sensitivity). In addition, we tested for interaction by sex and glucose metabolism status.

RESULTS

After full adjustment, lower time- and frequency-domain HRV was significantly associated with lower overall beta cell response composite score (standardized beta, -0.055 [-0.098; -0.011] and - 0.051 [-0.095; -0.007], respectively). These associations were not modified by sex and there was no consistent pattern of interaction by glucose metabolism status.

CONCLUSION

The present etiological study found that worse autonomic function, estimated from lower HRV, was associated with worse beta cell function, estimated from a composite score in a population-based sample which covered the entire spectrum of glucose metabolism. Hence, autonomic dysfunction may contribute to beta cell dysfunction and, ultimately, to the alteration of glucose metabolism status from normal glucose metabolism to prediabetes and type 2 diabetes.

Cardiometabolic risk factors, peripheral arterial tonometry and metformin in adults with type 1 diabetes participating in the REducing with MetfOrmin Vascular Adverse Lesions trial

BACKGROUND

Peripheral arterial tonometry (PAT) provides non-invasive measures of vascular health. Beneficial effects of metformin on vascular function have been reported in youth with type 1 diabetes (T1D). In the REducing with MetfOrmin Vascular Adverse Lesions (REMOVAL) trial in adults with T1D and high cardiovascular risk, we examined: (i) the extent to which routinely-measured cardiometabolic risk factors explain variance in baseline PAT; and (ii) the effects of metformin on PAT measures.

METHODS

Cross-sectional univariable and multivariable analyses of baseline reactive hyperaemia index (RHI) and augmentation index (AI) (EndoPAT® (Itamar, Israel); and analysis of 36-months metformin versus placebo on vascular tonometry.

RESULTS

In 364 adults ((mean ± SD) age 55.2 ± 8.5 years, T1D 34.0 ± 10.6 years, HbA1c 64.5 ± 9.0 mmol/mol (8.1 ± 0.8%)), RHI was 2.26 ± 0.74 and AI was 15.9 ± 19.2%. In an exhaustive search, independent associates of (i) RHI were smoking, waist circumference, systolic blood pressure and vitamin B12 (adjusted R² = 0.11) and (ii) AI were male sex, pulse pressure, heart rate and waist circumference (adjusted R² = 0.31). Metformin did not significantly affect RHI or AI.

CONCLUSION

Cardiometabolic risk factors explained only a modest proportion of variance in PAT measures of vascular health in adults with T1D and high cardiovascular risk. PAT measures were not affected by metformin.

Habitual intake of dietary dicarbonyls is associated with greater insulin sensitivity and lower prevalence of type 2 diabetes: The Maastricht Study

BACKGROUND

Dicarbonyls are reactive precursors of advanced glycation endproducts (AGEs). Dicarbonyls are formed endogenously, but also during food processing. Circulating dicarbonyls are positively associated with insulin resistance and type 2 diabetes, but consequences of dietary dicarbonyls are unknown.

OBJECTIVE

To examine the associations of dietary intake of dicarbonyls with insulin sensitivity, β-cell function, and prevalence of prediabetes or type 2 diabetes.

METHODS

In 6282 participants (60±9 years, 50% men, 23% type 2 diabetes (oversampled)) of the population-based cohort The Maastricht Study, we estimated habitual intake of the dicarbonyls methylglyoxal (MGO), glyoxal (GO), and 3-deoxyglucosone (3-DG) using Food Frequency Questionnaires. Insulin sensitivity (n=2390), β-cell function (n=2336) and glucose metabolism status (n=6282) were measured by a seven-point oral glucose tolerance test. Insulin sensitivity was assessed as the Matsuda index. Additionally, insulin sensitivity was measured as HOMA2-IR (n=2611). β-cell function was assessed as C-peptidogenic index, overall insulin secretion, glucose sensitivity, potentiation factor, and rate sensitivity. Cross-sectional associations of dietary dicarbonyls with these outcomes were investigated using linear or logistic regression adjusting for age, sex, cardio-metabolic risk-factors, lifestyle, and dietary factors.

RESULTS

Higher dietary MGO and 3-DG intakes were associated with greater insulin sensitivity after full adjustment, indicated by both a higher Matsuda index (MGO: Std. β [95% CI]=0.08 [0.04, 0.12] and 3-DG: 0.09 [0.05, 0.13]) and a lower HOMA2-IR (MGO: Std. β=-0.05 [-0.09, -0.01] and 3-DG: -0.04 [-0.08, -0.01]). Moreover, higher MGO and 3-DG intakes were associated with lower prevalence of newly diagnosed type 2 diabetes (OR [95%CI]=0.78 [0.65, 0.93] and 0.81 [0.66, 0.99]). There were no consistent associations of MGO, GO, and 3-DG intakes with β-cell function.

CONCLUSIONS

Higher habitual consumption of the dicarbonyls MGO and 3-DG was associated with better insulin sensitivity and with lower prevalence of type 2 diabetes, after excluding individuals with known diabetes. These novel observations warrant further exploration in prospective cohorts and intervention studies.

Angiotensin-converting enzyme inhibitors and angiotensin receptor blockers and risk of depression among older people with hypertension

BACKGROUND

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs), commonly used antihypertensive drugs, may have a protective effect against depression in older individuals, but evidence in humans is limited.

AIMS

We evaluated the risk of depression, among older individuals with hypertension, comparing ACE or ARB initiators to thiazide(-like) diuretic initiators. Thiazide(-like) diuretics were used as control because these drugs are not associated with mood disorders.

METHODS

We used a propensity score-matched new user cohort design with routinely collected data from general practices in England from the Clinical Practice Research Datalink database. We matched 12,938 pairs of new users of ACEIs/ARBs and thiazide(-like) diuretics with hypertension (mean age 67.6 years; 54.7% women). Follow-up time started on the date of drug initiation and ended on the date of treatment discontinuation plus 30 days, or switch to a comparator, occurrence of a study event, death, date of patient's transfer out of practice, or end of the study period. The primary outcome was a composite endpoint of treated depression and nonfatal and fatal self-harm.

RESULTS/OUTCOMES

Compared to the thiazide(-like) diuretic group, ACEIs/ARBs use was not associated with a lower risk of the primary outcome (hazard ratio 0.96 (95% confidence interval: 0.79; 1.15)). Results did not differ according to lipophilicity, duration of use, and average daily dose, or class (ACEIs or ARBs).

CONCLUSIONS/INTERPRETATION

New use of ACEIs or ARBs is not associated with a lower risk of depression among individuals with hypertension.

A 4-week high-AGE diet does not impair glucose metabolism and vascular function in obese individuals

BACKGROUND

Accumulation of advanced glycation endproducts (AGEs) may contribute to the pathophysiology of type 2 diabetes and its vascular complications. AGEs are widely present in food, but whether restricting AGE intake improves risk factors for type 2 diabetes and vascular dysfunction is controversial.

METHODS

Abdominally obese but otherwise healthy individuals were randomly assigned to a specifically designed 4-week diet low or high in AGEs in a double-blind, parallel design. Insulin sensitivity, secretion, and clearance were assessed by a combined hyperinsulinemic-euglycemic and hyperglycemic clamp. Micro- and macrovascular function, inflammation, and lipid profiles were assessed by state-of-the-art in vivo measurements and biomarkers. Specific urinary and plasma AGEs N^ε-(carboxymethyl)lysine (CML), N^ε-(1-carboxyethyl)lysine (CEL), and N^δ-(5-hydro-5-methyl-4-imidazolon-2-yl)-ornithine (MG-H1) were assessed by mass spectrometry.

RESULTS

In 73 individuals (22 males, mean ± SD age and BMI 52 ± 14 years, 30.6 ± 4.0 kg/m²), intake of CML, CEL, and MG-H1 differed 2.7-, 5.3-, and 3.7-fold between the low- and high-AGE diets, leading to corresponding changes of these AGEs in urine and plasma. Despite this, there was no difference in insulin sensitivity, secretion, or clearance; micro- and macrovascular function; overall inflammation; or lipid profile between the low and high dietary AGE groups (for all treatment effects, P > 0.05).

CONCLUSION

This comprehensive RCT demonstrates very limited biological consequences of a 4-week diet low or high in AGEs in abdominally obese individuals.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT03866343; trialregister.nl, NTR7594.

FUNDING

Diabetesfonds and ZonMw.

Association between social network characteristics and prevalent and incident depression: The Maastricht Study

AIMS

Social network characteristics may provide a novel non-pharmaceutical target for the prevention of depression. We investigated the temporal association of a broad range of structural and functional social network characteristics with incident depressive symptoms over 5 years of follow-up.

METHODS

We used data from The Maastricht Study, a population-based prospective cohort study (n=2,465, mean age 59.8±8.1 years, 49.1% women, 11,585 person-years of follow-up). Social network characteristics were assessed through a name generator questionnaire. Clinically relevant depressive symptoms (9-item Patient Health Questionnaire score≥10) were assessed at baseline and annually. We used multivariable logistic and Cox regression analyses, adjusted for sociodemographic, lifestyle and cardiovascular risk factors.

RESULTS

In cross-sectional analyses less emotional support for discomfort and with important decisions, and less informational support were associated with prevalent depressive symptoms (OR[95%CI] 1.19 [1.01-1.40]; 1.22 [1.05-1.43], and 1.20 [1.04-1.39], respectively). Every fewer 10% of family members was associated with prevalent depressive symptoms (1.11 [1.01-1.23]). In longitudinal analyses, less emotional support on important decisions was also associated with higher risk of incident depressive symptoms (HR[95%CI] 1.13 [1.03-1.25]). In addition, every fewer 10% of the network that was a family member was associated with a higher hazard of incident depressive symptoms (1.07 [1.01-1.13]).

CONCLUSIONS

This study shows that less emotional support and fewer family members in the network were associated with higher risk of both prevalent and incident depression. The importance of emotional support and the role that family plays should be considered in treatment and prevention of depression.

The association of markers of cerebral small vessel disease and brain atrophy with incidence and course of depressive symptoms - the maastricht study

BACKGROUND

Cerebral small vessel disease (CSVD) and neurodegeneration may be involved in the development and persistence of late-life depressive symptoms, but longitudinal evidence is scarce. We investigated the longitudinal associations of markers of CSVD and brain atrophy with incident depressive symptoms and the course of depressive symptoms, above and below 60 years of age.

METHODS

White matter hyperintensity volumes (WMH), presence of lacunar infarcts and cerebral microbleeds, and white matter, grey matter, and cerebral spinal fluid volumes were assessed at baseline by 3T MRI in The Maastricht Study (mean age 59.5±8.5 years, 49.6% women, n=4,347; 16,535 person-years of follow-up). Clinically relevant depressive symptoms (9-item Patient Health Questionnaire≥10) were assessed at baseline and annually over seven years. We used Cox regression and multinomial logistic regression analyses adjusted for demographic, cardiovascular, and lifestyle risk factors.

RESULTS

Above 60 years of age, larger WMH volumes were associated with an increased risk for incident depressive symptoms (HR[95%CI]:1.24[1.04;1.48] per SD) and a persistent course of depressive symptoms (OR:1.44[1.04;2.00] per SD). Total CSVD burden was associated with persistent depressive symptoms irrespective of age (adjusted OR:1.58[1.03;2.43]), while no associations were found for general markers of brain atrophy.

LIMITATIONSS

Our findings need replication in other large-scale population-based studies.

CONCLUSIONS

Our findings may suggest a temporal association of larger WMH volume with the incidence and persistence of late-life depression in the general population and may provide a potential target for the prevention of chronic late-life depression.

Serial measurements in COVID-19-induced acute respiratory disease to unravel heterogeneity of the disease course: design of the Maastricht Intensive Care COVID cohort (MaastrICCht)

INTRODUCTION

The course of the disease in SARS-CoV-2 infection in mechanically ventilated patients is unknown. To unravel the clinical heterogeneity of the SARS-CoV-2 infection in these patients, we designed the prospective observational Maastricht Intensive Care COVID cohort (MaastrICCht). We incorporated serial measurements that harbour aetiological, diagnostic and predictive information. The study aims to investigate the heterogeneity of the natural course of critically ill patients with a SARS-CoV-2 infection.

METHODS AND ANALYSIS

Mechanically ventilated patients admitted to the intensive care with a SARS-CoV-2 infection will be included. We will collect clinical variables, vital parameters, laboratory variables, mechanical ventilator settings, chest electrical impedance tomography, ECGs, echocardiography as well as other imaging modalities to assess heterogeneity of the course of a SARS-CoV-2 infection in critically ill patients. The MaastrICCht is also designed to foster various other studies and registries and intends to create an open-source database for investigators. Therefore, a major part of the data collection is aligned with an existing national intensive care data registry and two international COVID-19 data collection initiatives. Additionally, we create a flexible design, so that additional measures can be added during the ongoing study based on new knowledge obtained from the rapidly growing body of evidence. The spread of the COVID-19 pandemic requires the swift implementation of observational research to unravel heterogeneity of the natural course of the disease of SARS-CoV-2 infection in mechanically ventilated patients. Our study design is expected to enhance aetiological, diagnostic and prognostic understanding of the disease. This paper describes the design of the MaastrICCht.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the medical ethics committee (Medisch Ethische Toetsingscommissie 2020-1565/3 00 523) of the Maastricht University Medical Centre+ (Maastricht UMC+), which will be performed based on the Declaration of Helsinki. During the pandemic, the board of directors of Maastricht UMC+ adopted a policy to inform patients and ask their consent to use the collected data and to store serum samples for COVID-19 research purposes. All study documentation will be stored securely for fifteen years after recruitment of the last patient. The results will be published in peer-reviewed academic journals, with a preference for open access journals, while particularly considering deposition of the manuscripts on a preprint server early.

TRIAL REGISTRATION NUMBER

The Netherlands Trial Register (NL8613).

Glucocorticoids affect metabolic but not muscle microvascular insulin sensitivity following high versus low salt intake

BACKGROUNDSalt-sensitive hypertension is often accompanied by insulin resistance in obese individuals, but the underlying mechanisms are obscure. Microvascular function is known to affect both salt sensitivity of blood pressure and metabolic insulin sensitivity. We hypothesized that excessive salt intake increases blood pressure and decreases insulin-mediated glucose disposal, at least in part by impairing insulin-mediated muscle microvascular recruitment (IMMR).METHODSIn 20 lean and 20 abdominally obese individuals, we assessed mean arterial pressure (MAP; 24-hour ambulatory blood pressure measurements), insulin-mediated whole-body glucose disposal (M/I value; hyperinsulinemic-euglycemic clamp technique), IMMR (contrast-enhanced ultrasound), osmolyte and water balance, and excretion of mineralocorticoids, glucocorticoids, and amino and organic acids after a low- and high-salt diet during 7 days in a randomized, double-blind, crossover design.RESULTSOn a low-, as compared with a high-salt, intake, MAP was lower, M/I value was lower, and IMMR was greater in both lean and abdominally obese individuals. In addition, natural logarithm IMMR was inversely associated with MAP in lean participants on a low-salt diet only. On a high-salt diet, free water clearance decreased, and excretion of glucocorticoids and of amino acids involved in the urea cycle increased.CONCLUSIONOur findings imply that hemodynamic and metabolic changes resulting from alterations in salt intake are not necessarily associated. Moreover, they are consistent with the concept that a high-salt intake increases muscle glucose uptake as a response to high salt-induced, glucocorticoid-driven muscle catabolism to stimulate urea production and thereby renal water conservation.TRIAL REGISTRATIONClinicalTrials.gov, NCT02068781.

Progression of conventional cardiovascular risk factors and vascular disease risk in individuals: insights from the PROG-IMT consortium

AIMS

Averaged measurements, but not the progression based on multiple assessments of carotid intima-media thickness, (cIMT) are predictive of cardiovascular disease (CVD) events in individuals. Whether this is true for conventional risk factors is unclear.

METHODS AND RESULTS

An individual participant meta-analysis was used to associate the annualised progression of systolic blood pressure, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol with future cardiovascular disease risk in 13 prospective cohort studies of the PROG-IMT collaboration (n = 34,072). Follow-up data included information on a combined cardiovascular disease endpoint of myocardial infarction, stroke, or vascular death. In secondary analyses, annualised progression was replaced with average. Log hazard ratios per standard deviation difference were pooled across studies by a random effects meta-analysis. In primary analysis, the annualised progression of total cholesterol was marginally related to a higher cardiovascular disease risk (hazard ratio (HR) 1.04, 95% confidence interval (CI) 1.00 to 1.07). The annualised progression of systolic blood pressure, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol was not associated with future cardiovascular disease risk. In secondary analysis, average systolic blood pressure (HR 1.20 95% CI 1.11 to 1.29) and low-density lipoprotein cholesterol (HR 1.09, 95% CI 1.02 to 1.16) were related to a greater, while high-density lipoprotein cholesterol (HR 0.92, 95% CI 0.88 to 0.97) was related to a lower risk of future cardiovascular disease events.

CONCLUSION

Averaged measurements of systolic blood pressure, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol displayed significant linear relationships with the risk of future cardiovascular disease events. However, there was no clear association between the annualised progression of these conventional risk factors in individuals with the risk of future clinical endpoints.

Abdominal subcutaneous and visceral adipocyte size, lipolysis and inflammation relate to insulin resistance in male obese humans

Obesity is associated with a disturbed adipose tissue (AT) function characterized by adipocyte hypertrophy, an impaired lipolysis and pro-inflammatory phenotype, which contributes to insulin resistance (IR). We investigated whether AT phenotype in different AT depots of obese individuals with and without type 2 diabetes mellitus (T2DM) is associated with whole-body IR. Subcutaneous (SC) and visceral (V) AT biopsies from 18 lean, 17 obese and 8 obese T2DM men were collected. AT phenotype was characterized by ex vivo measurement of basal and stimulated lipolysis (mature adipocytes), adipocyte size distribution (AT tissue sections) and AT immune cells (flow cytometry). In VAT, mean adipocyte size, CD45⁺ leukocytes and M1 macrophages were significantly increased in both obese groups compared to lean individuals. In SCAT, despite adipocyte hypertrophy, no significant differences in immune cell populations between groups were found. In SCAT, multiple linear regression analysis showed that none of the AT phenotype markers independently contributed to HOMA-IR while in VAT, mean adipocyte size was significantly related to HOMA-IR. In conclusion, beside adipocyte hypertrophy in VAT, M1 macrophage- or B-cell-mediated inflammation, may contribute to IR, while inflammation in hypertrophic SCAT does not seem to play a major role in IR.

Independent tissue contributors to obesity-associated insulin resistance

BACKGROUND

Induction of insulin resistance is a key pathway through which obesity increases risk of type 2 diabetes, hypertension, dyslipidemia, and cardiovascular events. Although the detrimental effects of obesity on insulin sensitivity are incompletely understood, accumulation of visceral, subcutaneous, and liver fat and impairment of insulin-induced muscle microvascular recruitment (MVR) may be involved. As these phenotypic changes often coincide in obesity, we aimed to unravel whether they independently contribute to insulin resistance and thus constitute separate targets for intervention.

METHODS

We measured visceral (VAT) and subcutaneous adipose tissue (SAT) volumes and intrahepatic lipid (IHL) content by MRI, and whole body glucose disposal (WBGD) and MVR (using contrast-enhanced ultrasound) responses to a euglycemic insulin clamp in lean (n = 25) and abdominally obese men (n = 52). Abdominally obese men were randomized to dietary weight loss intervention or habitual diet.

RESULTS

Obesity-associated increases in VAT, SAT, and IHL, along with the decrease in MVR, contributed independently to insulin resistance. Moreover, a dietary weight loss intervention reduced insulin resistance, and mediation analyses showed that decreased IHL and insulin-induced MVR, but not decreased VAT or SAT volumes, independently contributed to improved insulin resistance seen with weight loss.

CONCLUSION

Quantifying the mutually independent contributions of visceral and subcutaneous adipose tissue, intrahepatic lipid, and insulin-induced muscle microvascular recruitment reveals distinct targets for treating obesity-associated insulin resistance.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01675401.

FUNDING

Funding was from the Top Institute Food and Nutrition.

Diet-induced weight loss improves not only cardiometabolic risk markers but also markers of vascular function: a randomized controlled trial in abdominally obese men

BACKGROUND

Many trials assessing effects of dietary weight loss on vascular function have been performed without no-weight loss control groups and in individuals with obesity-related morbidities. Usually a limited set of vascular function markers has been investigated.

OBJECTIVE

The objective of this study was to examine effects of diet-induced weight loss on various vascular function markers and differences between normal-weight and abdominally obese men at baseline and after weight reduction.

DESIGN

Twenty-five healthy, normal-weight men (waist circumference: <94 cm) and 54 abdominally obese men (waist circumference: 102-110 cm) participated. Abdominally obese participants were randomly allocated to a dietary weight-loss or a no-weight loss control group. Individuals from the weight-loss group followed a calorie-restricted diet for 6 wk to obtain a waist circumference <102 cm followed by a weight-maintenance period of 2 wk. The control group maintained their habitual diet and physical activity levels. The primary outcome was the change in brachial artery flow-mediated vasodilation (FMD).

RESULTS

Compared with the control group, FMD did not change in the weight-loss group, but carotid-to-femoral pulse wave velocity tended to decrease by 0.5 m/s (P = 0.065). The retinal arteriolar caliber increased by 5 μm (P < 0.001) and the arteriolar-to-venular ratio by 0.02 (P < 0.01). Soluble endothelial selectin and soluble intercellular adhesion molecule concentrations decreased (P < 0.001). Also, total cholesterol, low-density lipoprotein cholesterol, triacylglycerol, glucose, insulin, C-peptide, homeostasis model assessment of insulin resistance, and blood pressure improved (P < 0.05 for all variables). Except for FMD, these markers differed at baseline between normal-weight and abdominally obese men but became comparable after weight loss.

CONCLUSIONS

In abdominally obese men, dietary weight loss targeting a waist circumference of <102 cm improved retinal microvascular caliber, plasma biomarkers of microvascular endothelial function, and the more conventional cardiometabolic risk markers. Aortic stiffness tended to decrease, but FMD was not changed. This trial was registered at clinicaltrials.gov as NCT01675401.

Association of dietary protein and dairy intakes and change in renal function: results from the population-based longitudinal Doetinchem cohort study

BACKGROUND

Evidence has suggested that protein from dairy may be less detrimental to renal health than protein from nondairy products. However, to our knowledge, no previous studies have used cystatin C-based measures of the estimated glomerular filtration rate (eGFR).

OBJECTIVE

We investigated the associations of sources of protein and dairy with the change in the eGFR in persons with a normal or mildly decreased eGFR.

DESIGN

We included 3798 participants, aged 26-65 y, from the Doetinchem Cohort study who were examined ≥3 times 5 y apart. Intakes of protein and dairy and subtypes of protein and dairy were assessed at each round. With the use of the Chronic Kidney Disease Epidemiology Collaboration equation, the eGFR was estimated from cystatin C with all available samples per participant examined in one assay run. Generalized estimating equation models, which were adjusted for lifestyle, biological, and other dietary factors (monounsaturated fat, polyunsaturated fat, phosphorus, magnesium, calcium, and vitamin D) were performed.

RESULTS

The mean baseline eGFR in the total cohort and in subjects with a mildly decreased eGFR (≥1 eGFR of 60-90 mL · min^-1 · 1.73 m^-2 during follow-up; n = 1326) was 108.6 and 95.2 mL · min^-1 · 1.73 m^-2, and the mean annual decline in both groups was 1.01 and 1.34 mL · min^-1 · 1.73 m^-2, respectively. Intakes of total, vegetable, animal, and nondairy protein, dairy protein, cheese, total dairy, high-fat dairy, and fermented dairy were not associated with eGFR changes. In individuals with a mildly decreased eGFR, higher consumption of milk, milk products, and low-fat dairy was associated with less annual decline in the eGFR (P-trend = 0.003). These associations were partially explained by dietary components of dairy (monounsaturated fat, polyunsaturated fat, phosphorus, magnesium, calcium, and vitamin D; P-trend < 0.04).

CONCLUSIONS

Higher low-fat dairy consumption, but not sources of protein, is associated with less annual decline in the eGFR, particularly in individuals with a mildly decreased eGFR. These associations are partly attributable to other major components of dairy. Confirmation of these results will improve our ability to understand the role of dairy consumption in the prevention of renal dysfunction.

Serum advanced glycation endproducts are associated with left ventricular dysfunction in normal glucose metabolism but not in type 2 diabetes: The Hoorn Study

OBJECTIVE

To investigate whether serum advanced glycation endproducts are associated with left ventricular systolic and diastolic function in participants with normal glucose metabolism, impaired glucose metabolism and type 2 diabetes mellitus.

METHODS

Participants from a cross-sectional, population-based study (n = 280 with normal glucose metabolism, n = 171 with impaired glucose metabolism, n = 242 with type 2 diabetes mellitus) underwent echocardiography. Serum protein-bound advanced glycation endproducts [i.e. Nε-(carboxymethyl)lysine, pentosidine and Nε-(carboxyethyl)lysine] were measured. Linear regression analyses were used and stratified according to glucose metabolism status.

RESULTS

In normal glucose metabolism, higher Nε-(carboxymethyl)lysine and pentosidine levels were associated with worse diastolic function (left atrial volume index and left atrial volume × left ventricular mass index product term) and higher Nε-(carboxymethyl)lysine and Nε-(carboxyethyl)lysine levels with worse systolic function (ejection fraction). In impaired glucose metabolism, a similar pattern emerged, though less consistent. In type 2 diabetes mellitus, these associations were non-existent for diastolic function or even reversed for systolic function.

CONCLUSION

This suggests that serum advanced glycation endproducts are associated with impaired left ventricular function in normal glucose metabolism, but that with deteriorating glucose metabolism status, serum advanced glycation endproducts may not mirror heart failure risk.

Coffee and tea consumption in relation to estimated glomerular filtration rate: results from the population-based longitudinal Doetinchem Cohort Study

BACKGROUND

Although coffee consumption and tea consumption have been linked to diabetes, the relation with kidney function is less clear and is underresearched.

OBJECTIVE

We investigated the prospective associations of coffee and tea consumption with estimated glomerular filtration rate (eGFR).

DESIGN

We included 4722 participants aged 26-65 y from the Doetinchem Cohort Study who were examined every 5 y for 15 y. Coffee and tea consumption (in cups/d) were assessed at each round. eGFR was assessed by using the Chronic Kidney Disease Epidemiology Collaboration equation based on both plasma creatinine and cystatin C. We determined the association between categories of coffee and tea intake and 1) eGFR and 2) subsequent annual changes in eGFR by using generalized estimating equation analyses.

RESULTS

Baseline mean ± SD eGFR was 108.0 ± 14.7 mL · min(-1) · 1.73 m(-2) Tea consumption was not associated with eGFR. Those individuals who drank >6 cups coffee/d had a 1.33 (95% CI: 0.24, 2.43) mL · min(-1) · 1.73 m(-2) higher eGFR than those who drank <1 cup/d (P-trend = 0.02). This association was most apparent among those with a median age of ≥46 y at baseline, with eGFR being 2.47 (95% CI: 0.42, 4.51) mL · min(-1) · 1.73 m(-2) higher in participants drinking >6 cups/d compared with <1 cup/d (P-trend = 0.02). Adjustment for biological risk factors and coffee constituents did not attenuate the associations. Neither coffee nor tea consumption was associated with changes in eGFR.

CONCLUSIONS

Coffee consumption was associated with a slightly higher eGFR, particularly in those aged ≥46 y. The absence of an association with eGFR changes suggests that the higher eGFR among coffee consumers is unlikely to be a result of glomerular hyperfiltration. Therefore, low to moderate coffee consumption is not expected to be a concern for kidney health in the general population.

Symptom burden and its association with change in glucose metabolism status over a 7-year period: the Hoorn Study

AIMS

To study symptom burden among older people and its associations with change in glucose metabolism status over a 7-year period.

METHODS

We conducted a prospective population-based cohort study among 397 older people. We used the revised Diabetes Symptom Checklist to assess symptom burden. Glucose metabolism status was determined using an oral glucose tolerance test. Analyses were adjusted for multiple confounders, including cardiovascular risk and risk of depression (Center for Epidemiological Studies Depression Scale score ≥ 16).

RESULTS

Revised Diabetes Symptom Checklist total scores (range 0-100) increased slightly over time among people with normal glucose metabolism (mean difference β1.04; P = 0.04) and those with impaired glucose metabolism (β1.96; P = 0.01), but not among people with Type 2 diabetes (β0.46; P = 0.55). These associations between symptom burden and glucose status were attenuated after full adjustment for multiple confounders and remained statistically significant for those with impaired glucose status. Linear mixed models showed significant mean differences in revised Diabetes Symptom Checklist total scores over time when comparing people with Type 2 diabetes with those with normal or impaired glucose metabolism, but not when comparing subjects with impaired vs normal glucose metabolism; these results did not alter after full adjustment.

CONCLUSIONS

Symptom burden increased gradually over time in the people with impaired glucose metabolism and those with normal glucose metabolism, but not in patients with Type 2 diabetes over a 7-year follow-up period.

HbA1c, fasting and 2 h plasma glucose in current, ex- and never-smokers: a meta-analysis

AIMS/HYPOTHESIS

The relationships between smoking and glycaemic variables have not been well explored. We compared HbA1c, fasting plasma glucose (FPG) and 2 h plasma glucose (2H-PG) in current, ex- and never-smokers.

METHODS

This meta-analysis used individual data from 16,886 men and 18,539 women without known diabetes in 12 DETECT-2 consortium studies and in the French Data from an Epidemiological Study on the Insulin Resistance Syndrome (DESIR) and Telecom studies. Means of three glycaemic variables in current, ex- and never-smokers were modelled by linear regression, with study as a random factor. The I (2) statistic was used to evaluate heterogeneity among studies.

RESULTS

HbA1c was 0.10% (95% CI 0.08, 0.12) (1.1 mmol/mol [0.9, 1.3]) higher in current smokers and 0.03% (0.01, 0.05) (0.3 mmol/mol [0.1, 0.5]) higher in ex-smokers, compared with never-smokers. For FPG, there was no significant difference between current and never-smokers (-0.004 mmol/l [-0.03, 0.02]) but FPG was higher in ex-smokers (0.12 mmol/l [0.09, 0.14]). In comparison with never-smokers, 2H-PG was lower (-0.44 mmol/l [-0.52, -0.37]) in current smokers, with no difference for ex-smokers (0.02 mmol/l [-0.06, 0.09]). There was a large and unexplained heterogeneity among studies, with I (2) always above 50%; I (2) was little changed after stratification by sex and adjustment for age and BMI. In this study population, current smokers had a prevalence of diabetes that was 1.30% higher as screened by HbA1c and 0.52% lower as screened by 2H-PG, in comparison with never-smokers.

CONCLUSION/INTERPRETATION

Across this heterogeneous group of studies, current smokers had a higher HbA1c and lower 2H-PG than never-smokers. This will affect the chances of smokers being diagnosed with diabetes.

BclI glucocorticoid receptor polymorphism is associated with greater body fatness: the Hoorn and CODAM studies

CONTEXT

The BclI polymorphism in the glucocorticoid receptor (GR) gene is associated with enhanced glucocorticoid (GC) sensitivity.

OBJECTIVE

Our objective was to investigate the association of the BclI polymorphism with body fatness and insulin resistance.

DESIGN AND SETTING

We conducted an observational cohort study, combining data from 2 cohort studies enriched with individuals with impaired glucose metabolism and/or diabetes mellitus type 2 (DM2).

PATIENTS AND METHODS

We examined 1228 participants (mean age 64.7 years, 45% women) from the Cohort Study on Diabetes and Atherosclerosis Maastricht (CODAM, n = 543) and the Hoorn Study (n = 685). Body mass index (BMI), waist and hip circumferences, and waist-to-hip ratio (WHR) were obtained; insulin resistance was estimated using the homeostasis model assessment for insulin resistance (HOMA2-IR).

RESULTS

We identified 519 noncarriers (CC), 540 heterozygous (CG) carriers, and 169 homozygous (GG) carriers of the G-allele of the BclI polymorphism. Homozygous carriers had a higher BMI (28.9 vs 27.9 kg/m(2)) and waist (99.6 vs 97.2 cm) and hip (105.5 vs 103.2 cm) circumference compared with noncarriers, also after adjustment for age, sex, cohort, glucose tolerance, and lifestyle risk factors: β = 0.94 kg/m(2) (95% confidence interval, 0.24-1.63), β = 2.84 cm (0.95;4.73) and β = 2.38 cm (0.88-3.87), respectively. Similar results were obtained when comparing homozygous carriers with heterozygous carriers: β = 1.03 kg/m(2) (0.34-1.72), β = 2.20 cm (0.31-4.08) and β = 1.99 cm (0.51-3.48), respectively. There were no differences in WHR. Ln-HOMA2-IR was higher in GG carriers compared with CG carriers; 0.29 vs 0.17 [β = 0.09 (0.01-0.17)], but this effect was attenuated after adjustment for BMI [β = 0.04 (-0.04 to 0.11)].

CONCLUSION

Homozygous carriers of the BclI polymorphism of the GR gene have significantly greater total body fatness, contributing to higher HOMA2-IR, compared with heterozygous carriers and noncarriers.

Comparison of fatty acid proportions in serum cholesteryl esters among people with different glucose tolerance status: the CoDAM study

BACKGROUND AND AIM

Altered fatty acid patterns in blood may be associated with insulin resistance and related disorders. We investigated whether serum proportions of cholesteryl fatty acids and desaturase activity are associated with glucose tolerance status and insulin resistance.

METHODS AND RESULTS

Data were obtained from a cross-sectional study among 471 Dutch participants aged ≥40 years. Individual fatty acids in serum cholesteryl esters were determined and endogenous conversions by desaturases were estimated from product-to-precursor ratios. Proportions of fatty acids were compared among participants with normal glucose tolerance, impaired glucose metabolism and newly diagnosed type 2 diabetes. Partial Spearman correlation coefficients between fatty acids and homeostasis model assessment-insulin resistance (HOMA-IR) were calculated. Adjustments were made for lifestyle and nutritional factors. The proportions of total saturated, mono-unsaturated, trans- and poly-unsaturated fatty acids did not differ significantly between groups, but several individual fatty acids did; the proportions of C18:0 and C20:3n6 were higher, whereas those of C18:1n7 and C20:4n6 were lower in participants with type 2 diabetes compared with those with normal glucose tolerance. Activity of Δ5-desaturase, that is, ratio of C20:4n6 to C20:3n6, was lower (p < 0.01) in participants with type 2 diabetes (7.4) than with normal glucose tolerance (8.4). HOMA-IR was correlated positively with Δ9-desaturase activity (r = 0.11, p < 0.01) and inversely with Δ5-desaturase activity (r = -0.21, p < 0.01).

CONCLUSION

The observed lower Δ5-desaturase activity in participants with type 2 diabetes and its inverse association with HOMA-IR suggest that changes in fatty-acid metabolism may play a role in the aetiology of type 2 diabetes.

Long-term exposure to traffic-related air pollution and type 2 diabetes prevalence in a cross-sectional screening-study in the Netherlands

BACKGROUND

Air pollution may promote type 2 diabetes by increasing adipose inflammation and insulin resistance. This study examined the relation between long-term exposure to traffic-related air pollution and type 2 diabetes prevalence among 50- to 75-year-old subjects living in Westfriesland, the Netherlands.

METHODS

Participants were recruited in a cross-sectional diabetes screening-study conducted between 1998 and 2000. Exposure to traffic-related air pollution was characterized at the participants' home-address. Indicators of exposure were land use regression modeled nitrogen dioxide (NO2) concentration, distance to the nearest main road, traffic flow at the nearest main road and traffic in a 250 m circular buffer. Crude and age-, gender- and neighborhood income adjusted associations were examined by logistic regression.

RESULTS

8,018 participants were included, of whom 619 (8%) subjects had type 2 diabetes. Smoothed plots of exposure versus type 2 diabetes supported some association with traffic in a 250 m buffer (the highest three quartiles compared to the lowest also showed increased prevalence, though non-significant and not increasing with increasing quartile), but not with the other exposure metrics. Modeled NO2-concentration, distance to the nearest main road and traffic flow at the nearest main road were not associated with diabetes. Exposure-response relations seemed somewhat more pronounced for women than for men (non-significant).

CONCLUSIONS

We did not find consistent associations between type 2 diabetes prevalence and exposure to traffic-related air pollution, though there were some indications for a relation with traffic in a 250 m buffer.

The Nε-(carboxymethyl)lysine-RAGE axis: putative implications for the pathogenesis of obesity-related complications

Obesity is an important contributor to the burden of insulin resistance, Type 2 diabetes and cardiovascular disease. An important mechanism by which excess adiposity causes obesity-associated complications is the dysregulated production and secretion of biologically active molecules derived from adipocytes. These adipokines affect the vascular wall and contribute to the development of insulin resistance and Type 2 diabetes. However, factors that cause an increased production of pro-inflammatory adipokines, while decreasing anti-inflammatory adipokines, have not been fully clarified. Owing to local conditions in adipose tissue, that is, increased fatty acids, hypoxia and oxidative stress, we speculate that an increased formation of the major advanced lipoxidation end product, N^ε-(carboxymethyl)lysine (CML), may play a role. CML-adducts in proteins are major ligands for the receptor for advanced glycation end products (RAGE). The consequence of RAGE activation by CML is the activation of important signaling inflammatory pathways. The putative role of CML-modified proteins in obesity is addressed in this article. The identification of this pathway may provide an important strategy for novel therapeutic approaches against obesity-associated complications.

Greater arterial stiffness in polycystic ovary syndrome (PCOS) is an obesity--but not a PCOS-associated phenomenon

CONTEXT

Polycystic ovary syndrome (PCOS) and obesity are associated with cardiovascular disease, but it is unclear to what extent they contribute independently. Arterial stiffness might link obesity and PCOS to cardiovascular diseases.

OBJECTIVE

Our objective was to investigate whether PCOS in the presence or absence of obesity is linked with arterial stiffness.

DESIGN AND SETTING

We conducted a cross-sectional study, including 31 obese (18 with PCOS) and 39 lean (22 with PCOS) women.

INTERVENTIONS AND MAIN OUTCOME MEASURES

Estimates of arterial stiffness were obtained by ultrasonography (distensibility and compliance of carotid, femoral, and brachial arteries; carotid elastic modulus; and intima-media thickness) and pulse wave transit time analyses (carotid-femoral pulse wave velocity and aortic augmentation index).

RESULTS

Obese women, with or without PCOS, had stiffer arteries than lean women. After adjustment for 24-h mean arterial pressure and age, obesity was inversely associated with the femoral, brachial, and carotid distensibility coefficients [β (95% confidence interval), -0.354 (-0.614 to -0.094), -0.354 (-0.547 to -0.161), and -0.248 (-0.370 to -0.126) 10(-3)/kPA, respectively] and with the femoral and carotid compliance coefficients [-0.296 (-0.563 to -0.029) and -0.190 (-0.377 to -0.003) mm(2)/kPA, respectively] but not with the brachial compliance coefficient [-0.018 (-0.052-0.015) mm(2)/kPA], Young's elastic modulus [0.049 (-0.005-0.103) kPA], aortic pulse wave velocity and aortic augmentation index [0.050 msec (-0.959-1.058 msec) and -1.831% (-8.196-4.534%), respectively]. Analyses with waist circumference as key independent variable gave broadly similar results. In contrast, PCOS was not associated with arterial stiffness estimates after adjustment for the presence of obesity.

CONCLUSIONS

In young obese women with PCOS, (central) obesity, rather than PCOS itself, is associated with increased arterial stiffness. These data emphasize that, from the perspective of cardiovascular risk reduction, the focus should be on central fat mass reduction in obese women with PCOS.

ANTI-HSP60 and ANTI-HSP70 antibody levels and micro/ macrovascular complications in type 1 diabetes: the EURODIAB Study

OBJECTIVES

The heat shock proteins 60 and 70 (HSP60, HSP70) play an important role in cytoprotection. Under stress conditions they are released into the circulation and elicit an immune response. Anti-HSP60 and anti-HSP70 antibody levels have been associated with cardiovascular disease. Type 1 diabetes is associated with a greatly increased risk of micro- and macrovascular complications. Therefore, we investigated whether anti-HSP60 and anti-HSP70 antibody levels were associated with micro- and macrovascular complications in type 1 diabetic patients.

DESIGN

A cross-sectional nested case-control study from the EURODIAB Study of 531 type 1 diabetic patients was performed.

SUBJECTS

Cases (n = 363) were defined as those with one or more complications of diabetes; control subjects (n = 168) were all those with no evidence of any complication. We measured anti-HSP60 and anti-HSP70 antibody levels and investigated their cross-sectional associations with diabetic complications.

RESULTS

Anti-HSP70 antibody levels were significantly greater in control than in case subjects, whereas anti-HSP60 antibody levels were similar in the two groups. In logistic regression analysis, anti-HSP70 levels in the upper quartiles were associated with a 47% reduced odds ratio of micro/macrovascular complications, independently of conventional risk factors, markers of inflammation and endothelial dysfunction [odds ratio (OR) = 0.53, 95% confidence intervals (CI): 0.28-1.02].

CONCLUSIONS

In this large cohort of type 1 diabetic subjects, we found an independent and inverse association between serum anti-HSP70 antibody levels and diabetic micro/macrovascular complications. This suggests that anti-HSP70 antibody levels may be a novel marker of protection from chronic diabetic complications.

Effect of B vitamin supplementation on plasma homocysteine levels in celiac disease

AIM: To investigate the effect of vitamin supplements on homocysteine levels in patients with celiac disease.

METHODS: Vitamin B6, folate, vitamin B12, and fasting plasma homocysteine levels were measured in 51 consecutive adults with celiac disease [median (range) age 56 (18-63) years; 40% men, 26 (51%) had villous atrophy, and 25 (49%) used B-vitamin supplements] and 50 healthy control individuals matched for age and sex. Finally, the C677T polymorphism of 5,10-methylenetetrahydrofolate reductase (MTHFR) was evaluated in 46 patients with celiac disease and all control individuals.

RESULTS: Patients with celiac disease and using vitamin supplements had higher serum vitamin B6 (P = 0.003), folate (P < 0.001), and vitamin B12 (P = 0.012) levels than patients who did not or healthy controls (P = 0.035, P < 0.001, P = 0.007, for vitamin B6, folate, and vitamin B12, respectively). Lower plasma homocysteine levels were found in patients using vitamin supplements than in patients who did not (P = 0.001) or healthy controls (P = 0.003). However, vitamin B6 and folate, not vitamin B12, were significantly and independently associated with homocysteine levels. Twenty-four (48%) of 50 controls and 23 (50%) of 46 patients with celiac disease carried the MTHFR thermolabile variant T-allele (P = 0.89).

CONCLUSION: Homocysteine levels are dependent on Marsh classification and the regular use of B-vitamin supplements is effective in reduction of homocysteine levels in patients with celiac disease and should be considered in disease management.

Symptoms of depression in people with impaired glucose metabolism or Type 2 diabetes mellitus: The Hoorn Study

OBJECTIVE

To study the prevalence and risk factors of depressive symptoms, comparing subjects with normal glucose metabolism (NGM), impaired glucose metabolism (IGM) or Type 2 diabetes mellitus (DM2).

RESEARCH DESIGN AND METHODS

Cross-sectional data from a population-based cohort study conducted among 550 residents (276 men and 274 women) of the Hoorn region, the Netherlands. Levels of depressive symptoms were measured using the Centre for Epidemiologic Studies Depression Scale (CES-D score > or = 16). Glucose metabolism status was determined by means of fasting and post-load glucose levels.

RESULTS

The prevalence of depressive symptoms in men with NGM, IGM and DM2 was 7.7, 7.0 and 15.0% (P = 0.19) and for women 7.7, 23.1 and 19.7% (P < 0.01), respectively. Depression was significantly more common in women with IGM [odds ratio (OR) = 3.60, 95% confidence interval (CI) = 1.57 to 8.28] and women with DM2 (OR = 3.18, 95% CI = 1.31 to 7.74). In men, depression was not associated with IGM (OR = 0.90, 95% CI = 0.32 to 2.57) and non-significantly more common in DM2 (OR = 2.04, 95% CI = 0.75 to 5.49). Adjustment for cardiovascular risk factors, cardiovascular disease and diabetes symptoms reduced the strength of these associations.

CONCLUSIONS

Depressive symptoms are more common in women with IGM, but not men. Adjustment for cardiovascular risk factors, cardiovascular disease and diabetes symptoms partially attenuated these associations, suggesting that these variables could be intermediate factors.

Does microvascular dysfunction link obesity with insulin resistance and hypertension?

Obesity and obesity-associated clinical disorders are becoming an increasing public health burden. In this perspective, we postulate that impairment of microvascular function links obesity with insulin resistance and hypertension. Obesity is characterized by generalized microvascular dysfunction, which is associated with, and may precede, the development of insulin resistance and hypertension. Understanding of mechanisms involved in obesity-associated microvascular dysfunction may reveal new therapeutic targets. In obesity, cellular regulatory mechanisms of vasoreactivity are shifted towards vasoconstriction, with an increased role for endothelin-1 and a decreased role for nitric oxide. In addition, communicative pathways between adipose tissue and the microvasculature comprise increased release of adipokines and increased sympathetic activity. Although one mechanism may dominate, microvascular defects in obesity are probably caused by an integrated response consisting of endocrine, vasocrine and neurogenic mechanisms. This remains a fruitful area for future research.

An IGF-I promoter polymorphism modifies the relationships between birth weight and risk factors for cardiovascular disease and diabetes at age 36

OBJECTIVE

To investigate whether IGF-I promoter polymorphism was associated with birth weight and risk factors for cardiovascular disease (CVD) and type 2 diabetes (T2DM), and whether the birth weight--risk factor relationship was the same for each genotype.

DESIGN AND PARTICIPANTS

264 subjects (mean age 36 years) had data available on birth weight, IGF-I promoter polymorphism genotype, CVD and T2DM risk factors. Student's t-test and regression analyses were applied to analyse differences in birth weight and differences in the birth weight--risk factors relationship between the genotypes.

RESULTS

Male variant carriers (VCs) of the IGF-I promoter polymorphism had a 0.2 kg lower birth weight than men with the wild type allele (p = 0.009). Of the risk factors for CVD and T2DM, solely LDL concentration was associated with the genotype for the polymorphism. Most birth weight--risk factor relationships were stronger in the VC subjects; among others the birth weight--systolic blood pressure relationship: 1 kg lower birth weight was related to an 8.0 mmHg higher systolic blood pressure

CONCLUSION

The polymorphism in the promoter region of the IGF-I gene is related to birth weight in men only, and to LDL concentration only. Furthermore, the genotype for this polymorphism modified the relationships between birth weight and the risk factors, especially for systolic and diastolic blood pressure.

[Diastolic heart failure]

Diastolic heart failure is predominantly a disease of the elderly: at the age of 70 years, almost half of all patients with heart failure have diastolic heart failure. Hypertension and obesity are common underlying disorders in patients with diastolic heart failure. Patients with diastolic heart failure have an equal, or only slightly better, prognosis in terms of mortality compared to patients with systolic heart failure. Echocardiography can distinguish diastolic heart failure from systolic heart failure. Patients with heart failure and a normal ejection fraction almost certainly have a diastolic dysfunction. There is a lack of reliable data about the optimal medicinal treatment strategy for patients with diastolic heart failure. Angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, and (non-dihydropyridine) calcium antagonists have therapeutic potential. Digoxin may be contraindicated.

Progression of diabetic nephropathy: role of plasma homocysteine and plasminogen activator inhibitor-1

Among patients with diabetic nephropathy, the decline in glomerular filtration rate (GFR) varies substantially, ranging from 2 to 20 mL/min per year. Identification of predictors of progression in diabetic nephropathy is important. Plasma total homocysteine (tHcy) rises with urinary albumin excretion rate in diabetes, and plasminogen activator inhibitor-1 (PAI-1) has been correlated with increased matrix accumulation in various glomerulopathies. In this prospective observational cohort study, we evaluated the importance of baseline tHcy and PAI-1 as predictors of the rate of decline in GFR. Baseline tHcy and PAI-1 were measured in 157 type 1 diabetic patients with diabetic nephropathy (92 men; mean age, 41 +/- 10 years; mean diabetes duration, 27 +/- 8 years; median GFR, 80 mL/min/1.73 m(2) [range, 23 to 143 mL/min/1.73 m(2)]). Hereafter, GFR was measured yearly with a plasma clearance technique for at least 3 years (median, 7 years [range, 3.0 to 8.3 years]). The mean rate of decline in GFR was 3.7 +/- 0.3 mL/min per year. A linear regression analysis revealed a borderline significant relationship between rate of decline in GFR and tHcy (P = 0.069) and PAI-1 (P = 0.087). Analysis of the rate of decline in GFR and tertiles of tHcy and PAI-1 revealed that increasing levels of tHcy were correlated with a significantly faster decline in GFR (P = 0.025), whereas increasing levels of PAI-1 were not. After adjustment for other well-established risk factors for progression of nephropathy in a multiple linear regression analysis, however, neither tHcy levels nor PAI-1 levels were independent predictors of rate of decline in GFR.

Long-term homocysteine-lowering treatment with folic acid plus pyridoxine is associated with decreased blood pressure but not with improved brachial artery endothelium-dependent vasodilation or carotid artery stiffness: a 2-year, randomized, placebo-controlled trial

Homocysteine is associated with atherothrombotic disease, which may be mediated through associations of homocysteine levels with blood pressure, endothelial function, or arterial stiffness. In a placebo-controlled, randomized clinical trial, we measured blood pressure, brachial artery endothelium-dependent vasodilation, and common carotid artery stiffness in 158 clinically healthy siblings of patients with premature atherothrombotic disease at baseline and after 1 and 2 years of homocysteine-lowering treatment with folic acid (5 mg) plus pyridoxine (250 mg). Intention-to-treat analyses limited to participants (n=130) who underwent at least 1 measurement after the baseline visit showed that compared with placebo, treatment with folic acid plus pyridoxine was associated with a 3.7-mm Hg (95% CI -6.8 to -0.6 mm Hg) lower systolic and a 1.9-mm Hg (95% CI -3.7 to -0.02 mm Hg) lower diastolic blood pressure over the 2-year trial period. Together with the decreased occurrence of abnormal exercise electrocardiography tests reported previously, our results support the hypothesis that homocysteine-lowering treatment with folic acid plus pyridoxine has beneficial vascular effects. Because no effects could be demonstrated on brachial artery endothelium-dependent vasodilation or on common carotid artery stiffness, the present study does not support the hypothesis that the cardiovascular effects of homocysteine are mediated through these factors, at least in clinically healthy individuals.

Rapid progression of albumin excretion is an independent predictor of cardiovascular mortality in patients with type 2 diabetes and microalbuminuria

OBJECTIVE

In patients with type 2 diabetes, microalbuminuria is associated with an increase in predominantly cardiovascular mortality. Considerable interindividual variability in the rate of progression of microalbuminuria exists. The prognostic significance of rate of progression of microalbuminuria with regard to cardiovascular and renal clinical end points is, however, unknown. The purpose of this study was to determine the prognostic significance of rate of progression of microalbuminuria for cardiovascular end points and renal function.

RESEARCH DESIGN AND METHODS

In a previous prospective cohort study, progression of microalbuminuria (expressed as mean yearly change in albumin-to-creatinine ratio) was assessed in 58 patients with type 2 diabetes. During a median follow-up of 7 years after progression of microalbuminuria was determined, we registered all-cause mortality and coronary heart disease mortality as primary end points and coronary heart disease (fatal or nonfatal), peripheral vascular disease, ischemic stroke, retinopathy, macroalbuminuria, and change in serum creatinine as secondary end points.

RESULTS

Seven subjects died during the study; five of these subjects died of coronary heart disease. Cox's regression analysis identified progression of microalbuminuria as a significant predictor of all-cause mortality (hazard ratio 1.46 per point increase in albumin-to-creatinine ratio per year, P < 0.001), coronary heart disease mortality (hazard ratio 2.32, P = 0.006), and macroalbuminuria (hazard ratio 1.79, P < 0.001). Adjustment for multiple cardiovascular risk factors did not affect these results. Identical analyses for baseline level of microalbuminuria instead of progression rate of microalbuminuria did not show significant hazard ratios. In addition, progression of microalbuminuria significantly predicted an increase in serum creatinine (r = 0.29, P = 0.04).

CONCLUSIONS

In patients with type 2 diabetes and microalbuminuria, the rate of progression of albumin excretion seems to be a powerful independent predictor of mortality caused mainly by coronary heart disease.

Evidence for genetic factors explaining the association between birth weight and low-density lipoprotein cholesterol and possible intrauterine factors influencing the association between birth weight and high-density lipoprotein cholesterol: analysis in twins

Recent studies have demonstrated an association between low weight at birth and an atherogenic lipid profile in later life. To examine the influences of intrauterine and genetic factors, we investigated 53 dizygotic and 61 monozygotic adolescent twin pairs. Regression analysis demonstrated that low birth weight was associated with high levels of total cholesterol, low-density lipoprotein (LDL) cholesterol and apolipoprotein B (-0.17 mmol/liter per kg, P = 0.07; -0.18 mmol/liter per kg, P = 0.04; and -0.07 g/liter per kg, P = 0.02, respectively) and with low levels of high-density lipoprotein (HDL) cholesterol (+0.04 mmol/liter per kg, P = 0.1), after adjustment for age, sex, and body mass index. Intrapair differences in birth weight were significantly associated with differences in total cholesterol, LDL cholesterol, and apolipoprotein B in dizygotic twins after adjustment for differences in current body mass index (-0.49 mmol/liter per kg, P = 0.02; -0.51 mmol/liter per kg, P = 0.01; and -0.10 g/liter per kg, P = 0.04, respectively), demonstrating that the larger the difference in birth weight, the higher these risk factors in the twin with the lower birth weight, compared with the cotwin with the higher birth weight. In monozygotic twins, however, the associations between intrapair differences in birth weight and differences in total cholesterol, LDL cholesterol, and apolipoprotein B were in the opposite direction (+0.32 mmol/liter per kg, P = 0.03; +0.23 mmol/liter per kg, P = 0.08; and +0.06 g/liter per kg, P = 0.04, respectively). The association between intrapair differences in birth weight and differences in HDL cholesterol was not significant in dizygotic twins (+0.04 mmol/liter per kg, P = 0.6) and of borderline significance in monozygotic twins (+0.11 mmol/liter per kg, P = 0.05). These data suggest that genetic factors account for the association of low birth weight with high levels of total cholesterol, LDL cholesterol, and apolipoprotein B, whereas intrauterine factors possibly play a role in the association between birth weight and HDL cholesterol.

Intra-uterine and genetic influences on the relationship between size at birth and height in later life: analysis in twins

Epidemiological studies have consistently shown a positive association between size at birth (i.e. birth weight or birth length) and height in children, adolescents and adults. To examine whether this association is explained by genetic or nongenetic (intra-uterine) factors, we investigated birth weight, birth length and height in 60 dizygotic and 68 monozygotic adolescent twin pairs still living with their parents. Birth weight of the twins was obtained from their mothers. Height was measured in a standardised way. The mean age was 17+/-1.7 years for the dizygotic twins and 16+/-1.8 years for the monozygotic twins. Both dizygotic and monozygotic twins with the lowest birth weight from each pair had a height that was lower compared to their co-twins with the highest birth weight (dizygotic twins: 172.2+/-7.9 vs. 173.8+/-9.4 cm [p = 0.05]; monozygotic twins: 171.1+/-9.4 vs. 171.8+/-9.5 cm [p = 0.01]). Similarly, both dizygotic and monozygotic twins with the shortest birth length from each pair had a height that was lower compared to their co-twins with the longest birth length (dizygotic twins: 172.3+/-7.9 vs. 174.9plus minus9.7 cm [p < 0.05]; monozygotic twins: 168.9+/-10.6 vs. 169.9+/-10.2 cm [p < 0.01]). In addition, intra-pair differences in birth weight and birth length were significantly associated with differences in height in both dizygotic twins (regression coefficient: 4.3 cm/kg [95% confidence interval: 1.0 to 7.5] and 0.96 cm/cm [0.17 to 1.74], respectively) and monozygotic twins (2.8 cm/kg [1.4 to 4.1] and 0.73 cm/cm [0.40 to 1.06], respectively). These associations were stronger in dizygotic than in monozygotic twins, but this difference was not statistically significant (for birth weight p = 0.4; and for birth length p = 0.6). However, genetic model fitting indicated that models incorporating a genetic source of the covariance gave a better description of the observed association of birth weight and length with height in later life than models not incorporating this genetic source. The results were similar for data on adult height after 12 years of follow-up in a subgroup of these twin pairs. These data suggest that the association between size at birth and height in later life is influenced by non-genetic intra-uterine and by genetic factors.

Impaired autonomic function is associated with increased mortality, especially in subjects with diabetes, hypertension, or a history of cardiovascular disease: the Hoorn Study

OBJECTIVE

Measures of baroreflex sensitivity, heart rate variability (HRV), and the classical Ewing test parameters are currently used for the diagnosis of diabetic autonomic neuropathy and for mortality risk stratification after myocardial infarction. However, the strengths of the associations of these measures of autonomic function with risk of mortality have never been compared in one study population. Furthermore, no evidence is available on the possible effect of glucose tolerance on these associations.

RESEARCH DESIGN AND METHODS

The study population (n = 605) consisted of a glucose tolerance-stratified sample from a general population (50-75 years of age). Cardiac cycle duration and continuous finger arterial pressure were measured under two conditions: at rest and on metronome breathing. From these readings, seven parameters of autonomic function were assessed (one Ewing, five HRV, and one baroreflex sensitivity).

RESULTS

During 9 years of follow-up, 101 individuals died, 43 from cardiovascular causes. Subjects with diabetes and low levels of the autonomic function parameters, indicating impaired autonomic function, had an approximately doubled risk of mortality. This association was consistent, though not statistically significant, for all parameters. The elevated risk was not observed in subjects without diabetes, hypertension, or prevalent cardiovascular disease.

CONCLUSIONS

Impaired autonomic function is associated with all-cause and cardiovascular mortality. Moreover, the results of the present study suggest that cardiac autonomic dysfunction in patients already at risk (diabetes, hypertension, or history of cardiovascular disease) may be especially hazardous.

Markers of inflammation and cellular adhesion molecules in relation to insulin resistance in nondiabetic elderly: the Rotterdam study

Insulin resistance, which is highly prevalent in the elderly, is suggested to be accompanied by an increased acute phase response. Until now, it is unclear whether cellular adhesion molecules are involved in the clustering of insulin resistance. In the present study, we examined the relationship of insulin resistance (measured by postload insulin) with levels of markers of inflammation and cellular adhesion molecules in a random sample of 574 nondiabetic elderly men and women participating in the Rotterdam Study. Associations were assessed by regression analysis, with ln-insulin as the dependent variable [regression coefficient (95% confidence interval)]. In our population, insulin was strongly and significantly (P < 0.001) associated with the markers of inflammation C-reactive protein [1.52 (0.96-2.08)], alpha-1-antichymotrypsin [1.25 (0.82-1.69)], and IL-6 [2.60 (1.69-3.52)], adjusted for age and gender. Associations weakened, to some extent, after additional adjustment for measures of obesity, smoking, and cardiovascular disease. Insulin was associated with the soluble intercellular adhesion molecule 1 [2.22 (1.29-3.16; P < 0.001)], whereas no association with the soluble vascular cell adhesion molecule 1 was found. The strength of the associations of insulin with C-reactive protein, alpha-1-antichymotrypsin, IL-6, and soluble intercellular adhesion molecule 1, as assessed by standardized regression coefficients, was comparable with the strength of the associations of insulin with high-density lipoprotein cholesterol, body mass index, and waist-to-hip ratio. The results of this population-based study indicate that low-grade inflammation and the cellular adhesion molecule soluble intercellular adhesion molecule 1 are an integral part of insulin resistance in nondiabetic elderly. These factors may contribute to the well-known relationship between insulin resistance and cardiovascular disease risk and might potentially become therapeutic targets in insulin resistant subjects.

Homocysteine-lowering treatment: an overview

Elevated fasting plasma concentrations of homocysteine have a high prevalence in subjects with cardiovascular disease and have also been associated with an increased risk of atherothrombosis in most, but not all, prospective studies. The most frequent causes of hyperhomocysteinaemia are genetic defects, such as cystathionine-beta-synthase (CBS) deficiency, deficiencies of folic acid and/or vitamin B12, renal failure and interference in homocysteine metabolism by drugs or metabolic alterations. In most cases, no underlying cause can be established. Subjects with CBS deficiency are treated with pyridoxine with additional folic acid and betaine if necessary. Folic acid and vitamin B12 deficiencies should be corrected by supplementation. Increases in folate intake by dietary changes or fortification can also lower plasma homocysteine in vitamin-replete subjects with normal plasma homocysteine levels. In renal failure, folic acid treatment (1-5 mg/day) ameliorates the plasma homocysteine level in most cases but hyperhomocysteinaemia persists in the majority of patients. Primary (fasting) hyperhomocysteinaemia can be treated with folic acid (0.5-5 mg/day). An abnormal methionine-loading test identifies additional patients at risk and postmethionine-loading hyperhomocysteinaemia should be treated with a combination of pyridoxine and folic acid. In the absence of dose-effect studies, a combination of pyridoxine (50 mg) and folic acid (5 mg) is advised. Large clinical trials are currently underway to establish the role of homocysteine-lowering therapy in the secondary prevention of atherothrombotic disease. In view of the effective, cheap and safe character of therapy with folic acid and pyridoxine, a policy can be accepted to screen and treat high-risk patients until these trials have been concluded.

Brachial artery pulse pressure and common carotid artery diameter: mutually independent associations with mortality in subjects with a recent history of impaired glucose tolerance

BACKGROUND

Decreased large artery function, as reflected by increased brachial artery pulse pressure and increased carotid artery diameter and stiffness, may contribute to the increased mortality risk that is observed in subjects with impaired glucose tolerance. We therefore investigated the association between brachial artery pulse pressure and carotid artery diameter and stiffness, which are estimates of central artery stiffness and arterial remodelling, respectively, and mortality in subjects with a recent history of impaired glucose tolerance.

DESIGN

A prospective, population-based cohort study. We measured brachial artery pulse pressure by oscillometric blood pressure measurements, and common carotid artery diameter and distensibility and compliance coefficients by ultrasound in 140 subjects with a recent history of impaired glucose tolerance. During a median 6.6-year follow-up, 16 subjects died.

RESULTS

Brachial artery pulse pressure and common carotid artery diameter were positively related to all-cause mortality [hazard ratios per standard deviation, 1.7 (1.2-2.5) and 2.1 (1.3-3.3), respectively]. Results were similar after adjustment for gender, age, waist-to-hip ratio, body mass index, total cholesterol concentration, pre-existent cardiovascular disease, and hypertension, and after additional mutual adjustment. Common carotid artery distensibility and compliance coefficients were not statistically significantly associated with mortality.

CONCLUSIONS

Among subjects with a recent history of impaired glucose tolerance, brachial artery pulse pressure and common carotid artery diameter are independently associated with mortality risk. Stiffness of the central arteries may explain the association between pulse pressure and mortality risk. The association between carotid diameter and mortality risk is more likely to reflect arterial remodelling in response to atherosclerosis than that in response to increased local stiffness.

Impaired skin capillary recruitment in essential hypertension is caused by both functional and structural capillary rarefaction

Capillary rarefaction occurs in many tissues in patients with essential hypertension and may contribute to an increased vascular resistance and impaired muscle metabolism. Rarefaction may be caused by a structural (anatomic) absence of capillaries, functional nonperfusion, or both. The aim of this study was to assess the extent of structural versus functional capillary rarefaction in the skin of subjects with essential hypertension. We examined skin capillary density with video microscopy before and during maximization of the number of perfused capillaries by venous congestion (structural capillary number) and before and during postocclusive reactive hyperemia (capillary recruitment, which may have a structural and/or functional basis). The study group was composed of 26 patients with never-treated essential hypertension and 26 normotensive control subjects. In both groups, intermittently perfused capillaries in the resting state were an important functional reserve for recruitment during postocclusive hyperemia. Recruitment of perfused capillaries during postocclusive reactive hyperemia was decreased in the hypertensive subjects compared with normotensive control subjects (47.9+/-6.8 versus 55.3+/-8.2 capillaries/mm(2), respectively; P<0.01). During venous occlusion, maximal capillary density was significantly lower in the hypertensive subjects than in the control subjects (52.5+/-6.6 versus 57.2+/-8.6 capillaries/mm(2), respectively; P<0.05), suggesting structural rarefaction. However, in the hypertensive subjects compared with the normotensive subjects, a smaller proportion of the maximal number of capillaries was perfused during postocclusive hyperemia (91.6+/-7.5% versus 97.2+/-2.7%, respectively; P<0.05), suggesting an additional functional impairment of capillary recruitment. If the difference in capillary numbers during venous congestion ( approximately 4.6 capillaries/mm(2)) truly reflects the structural difference between the normotensive and hypertensive subjects, then, at most, 62% (4.6/7.4x100%) of the difference in capillary numbers during postocclusive hyperemia ( approximately 7.4 capillaries/mm(2)) can be explained by structural defects, and at least 38% can be explained by functional defects. In conclusion, in patients with essential hypertension, recruitment of perfused capillaries is impaired, which can be explained by both functional and structural rarefaction.

Heterogeneity of the association between plasma homocysteine and atherothrombotic disease: insights from studies of vascular structure and function

Among individuals with severe hyperhomocysteinaemia, there is a striking heterogeneity in the severity of the clinical features. This observation demonstrates that factors must exist that modulate the relationship between hyperhomocysteinaemia and clinical disease. Investigations of the association between mild-to-moderate hyperhomocysteinaemia and atherothrombotic disease also suggest heterogeneity in the association between plasma homocysteine levels and 1) clinical disease; 2) angiographic and echographic estimates of the extent of atherosclerosis; 3) arterial stiffness; 4) endothelial function; and 5) procoagulant status. The commonly held view that homocysteine is a vasculotoxic substance that promotes atherogenesis by causing endothelial damage is incomplete, because it cannot explain this heterogeneity. I suggest that homocysteine may have both prothrombotic and proatherogenic properties, but that there are strong, as yet unidentified enhancing and protective factors, the prevalence of which may differ among populations. This concept could account for some of the observed heterogeneity. Identifying these factors would be of major clinical importance and would provide crucial mechanistic insights.

Relation of impaired fasting and postload glucose with incident type 2 diabetes in a Dutch population: The Hoorn Study

CONTEXT

Persons with impaired glucose tolerance (IGT) are known to have an elevated risk of developing diabetes mellitus. Less is known about diabetes risk among persons with impaired fasting glucose (IFG) or with normal glucose levels.

OBJECTIVE

To determine the incidence of diabetes in relation to baseline fasting and postload glucose levels and other risk factors.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study conducted from October 1989 to February 1992 among 1342 nondiabetic white residents of Hoorn, the Netherlands, aged 50 to 75 years at baseline, in whom fasting plasma glucose (FPG) levels and glucose levels 2 hours after a 75-g oral glucose tolerance test were measured at baseline and at follow-up in 1996-1998.

MAIN OUTCOME MEASURES

Cumulative incidence of diabetes, defined according to the diagnostic criteria of the World Health Organization (WHO-1985 and WHO-1999) and the American Diabetes Association (ADA-1997), during a mean follow-up of 6.4 years, compared among participants with IFG, IGT, and normal glucose levels at baseline.

RESULTS

The cumulative incidence of diabetes was 6.1%, 8.3%, and 9.9% according to the WHO-1985, ADA, and WHO-1999 criteria, respectively. The cumulative incidence of diabetes (WHO-1999 criteria) for participants with both IFG and IGT was 64.5% compared with 4.5% for those with normal glucose levels at baseline. The odds ratios for diabetes (WHO-1999 criteria), adjusted for age, sex, and follow-up duration, were 10.0 (95% confidence interval [CI], 6.1-16.5), 10.9 (95% CI, 6.0-19.9), and 39.5 (95% CI, 17.0-92.1), respectively, for those having isolated IFG, isolated IGT, and both IFG and IGT. In addition to FPG and 2-hour postload glucose levels (P<.001 for both), the waist-hip ratio also was an important risk factor for developing diabetes (P =.002).

CONCLUSION

In this study, the cumulative incidence of diabetes was strongly related to both IFG and IGT at baseline and, in particular, to the combined presence of IFG and IGT.