Piet J. Kostense

The Effect of Exercise Training Programs on Bone Mass: A Meta- analysis of Published Controlled Trials in Pre- and Postmenopausal Women

Abstract: With the aging of the population, the medical and social costs of skeletal fragility leading to fractures will cause an immense burden on society unless effective prophylactic and therapeutic regimens can be developed. Exercise is suggested as a possible regimen against involutional bone loss. The purpose of the present meta-analysis is to address a quantitative review of the randomized controlled trials (RCTs) and nonrandomized controlled trials (CTs) on the effects of exercise training programs on bone mass, measured as bone mineral density (BMD) or bone mineral content (BMC), of the lumbar spine (LS) and the femoral neck (FN) in pre- and postmenopausal women. The literature from 1966 through December 1996 was searched for published RCTs and CTs. Study treatment effect is defined as the difference between percentage change in bone mass per year in the training group and the control group. Overall treatment effects (OTs) with the 95% confidence intervals of these study treatment effects were calculated using inverse-variance weighting. Of the 62 articles identified, 25 met the inclusion criteria and were maintained for further analyses. The weighted OTs for the RCTs showed very consistently that the exercise training programs prevented or reversed almost 1% of bone loss per year in both LS and FN for both pre- and postmenopausal women. The two OTs that could be calculated for strength training programs did not reach significance. The OTs for the CTs were almost twice as high as those for the RCTs, which gives an indication of the confounding introduced by the nonrandom allocation of the subjects to groups.

Arterial Stiffness Increases With Deteriorating Glucose Tolerance Status The Hoorn Study

Background—Type 2 diabetes (DM-2) and impaired glucose metabolism (IGM) are associated with an increased cardiovascular disease risk. In nondiabetic individuals, increased arterial stiffness is an important cause of cardiovascular disease. Associations between DM-2 and IGM and arterial stiffness have not been systematically investigated. Methods and Results—In a population-based cohort (n=747; 278 with normal glucose metabolism, 168 with IGM, and 301 with DM-2; mean age, 68.5 years), arterial stiffness was ultrasonically estimated by distensibility and compliance of the carotid, femoral, and brachial arteries and by the carotid elastic modulus. After adjustment for age, sex, and mean arterial pressure, DM-2 was associated with increased carotid, femoral, and brachial stiffness, whereas IGM was associated only with increased femoral and brachial stiffness. Carotid but not femoral or brachial stiffness increased from IGM to DM-2. Standardized &bgr;s (95% CI) for IGM and DM-2, compared with normal glucose metabolism, were −0.06 (−0.23 to 0.10) and −0.37 (−0.51 to −0.23) for carotid distensibility; −0.02 (−0.18 to 0.18) and −0.25 (−0.40 to −0.09) for carotid compliance; −0.05 (−0.23 to 0.13) and 0.25 (0.10 to 0.40) for carotid elastic modulus; −0.70 (−0.89 to −0.51) and −0.67 (−0.83 to −0.52) for femoral distensibility; and −0.62 (−0.80 to −0.44) and −0.79 (−0.94 to −0.63) for femoral compliance. The brachial artery followed a pattern similar to that of the femoral artery. Increases in stiffness indices were explained by decreases in distension, increases in pulse pressure, an increase in carotid intima-media thickness, and, for the femoral artery, a decrease in diameter. Hyperglycemia or hyperinsulinemia explained only 30% of the arterial changes associated with glucose tolerance. Adjustment for conventional cardiovascular risk factors did not affect these findings. Conclusions—IGM and DM-2 are associated with increased arterial stiffness. An important part of the increased stiffness occurs before the onset of DM-2 and is explained neither by conventional cardiovascular risk factors nor by hyperglycemia or hyperinsulinemia.

Microalbuminuria and Peripheral Arterial Disease Are Independent Predictors of Cardiovascular and All-Cause Mortality, Especially Among Hypertensive Subjects Five-year Follow-up of the Hoorn Study

Microalbuminuria (MA) is associated with increased cardiovascular and all-cause mortality. It has been proposed that MA reflects generalized atherosclerosis and may thus predict mortality. To investigate this hypothesis, we studied the associations between, on the one hand, MA and peripheral arterial disease (PAD), a generally accepted marker of generalized atherosclerosis, and, on the other hand, cardiovascular and all-cause mortality in an age-, sex-, and glucose tolerance-stratified sample (n=631) of a population-based cohort aged 50 to 75 years followed prospectively for 5 years. At baseline, the albumin-to-creatinine ratio (ACR) was measured in an overnight spot urine sample; MA was defined as ACR >2.0 mg/mmol. PAD was defined as an ankle-brachial pressure index below 0.90 and/or a history of a peripheral arterial bypass or amputation. After 5 years of follow-up, 58 subjects had died (24 of cardiovascular causes). Both MA and PAD were associated with a 4-fold increase in cardiovascular mortality. After adjusting for age, sex, diabetes mellitus, hypertension, levels of total and HDL-cholesterol and triglyceride, body mass index, smoking habits, and preexistent ischemic heart disease, the relative risks (RR) (95% confidence intervals) were 3.2 (1.3 to 8.1) for MA and 2.4 (0.9 to 6.1) for PAD. When both MA and PAD were included in the multivariate analysis, the RRs were 2.9 (1.1 to 7.3) for MA and 2.0 (0.7 to 5.7) for PAD. MA and PAD were both associated with an about 2-fold increase in all-cause mortality. The RRs of all-cause mortality associated with MA and PAD were about 4 times higher among hypertensive than among normotensive subjects. We conclude that both MA and PAD are associated with an increased risk of cardiovascular mortality. MA and PAD are mutually independent risk indicators. The associations of MA and PAD with all-cause mortality are somewhat weaker. They are more pronounced in the presence of hypertension than in its absence. These data suggest that MA affects mortality risk through a mechanism different from generalized atherosclerosis.

Increased Central Artery Stiffness in Impaired Glucose Metabolism and Type 2 Diabetes. The Hoorn Study

Abstract—Impaired glucose metabolism (IGM) and type 2 diabetes (DM-2) are associated with high cardiovascular disease risk. Increases in peripheral and central artery stiffness may represent pathophysiologic pathways through which glucose tolerance status leads to cardiovascular disease. Peripheral artery stiffness increases with deteriorating glucose tolerance status, whereas this trend remains unclear for central artery stiffness. Therefore, we investigated the associations between glucose tolerance status and estimates of central arterial stiffness. We performed a population-based study of 619 individuals (normal glucose metabolism, n=261; IGM, n=170; and DM-2, n=188) and assessed central artery stiffness by measuring total systemic arterial compliance, aortic pressure augmentation index, and carotid-femoral transit time. After adjustment for sex, age, heart rate, height, body mass index, and mean arterial pressure, DM-2 was associated with decreased total systemic arterial compliance, increased aortic augmentation index, and decreased carotid-femoral transit time. IGM was borderline significantly associated with decreased total systemic arterial compliance. Respective regression coefficients (95% confidence intervals) for IGM and DM-2 compared with normal glucose metabolism were −0.05 (−0.11 to 0.01) and −0.13 (−0.19 to −0.07) mL/mm Hg for total systemic arterial compliance; 1.1 (−0.2 to 2.5) and 1.6 (0.2 to 3.0) percentage points for aortic augmentation index; and −0.85 (−5.20 to 3.49) and −4.95 (−9.41 to −0.48) ms for carotid-femoral transit time. IGM and DM-2 are associated with increased central artery stiffness, which is more pronounced in DM-2. Deteriorating glucose tolerance is associated with increased central and peripheral arterial stiffness, which may partly explain why both DM-2 and IGM are associated with increased cardiovascular risk.

von Willebrand Factor, C-Reactive Protein, and 5-Year Mortality in Diabetic and Nondiabetic Subjects The Hoorn Study

Increased levels of von Willebrand factor (vWf) and C-reactive protein (CRP) predict cardiovascular mortality in selected populations. It is uncertain whether vWf and CRP predict mortality in a general population and whether vWf and CRP predict mortality through similar pathways. This study investigated the association of vWf and CRP with cardiovascular and all-cause mortality among diabetic and nondiabetic subjects. An age-, sex-, and glucose tolerance-stratified sample (n=631) of a population-based cohort aged 50 to 75 years was followed prospectively for 5 years. After 5 years of follow-up, 58 subjects had died (24 of cardiovascular causes). vWf (>1.56 IU/mL) and CRP (>2.84 mg/L) levels in the upper tertile were associated with, respectively, a 3- and 2-fold increase in cardiovascular mortality after adjustment for age, sex, and glucose tolerance status. Analyses in nondiabetic and diabetic subjects separately gave similar results. After further adjustment for hypertension, levels of HDL cholesterol and triglyceride, smoking habits, ischemic heart disease, and peripheral arterial disease, the relative risks (RRs) were 3.0 (95% CI 1.2 to 7.9) for vWf and 1.4 (95% CI 0.6 to 3.5) for CRP. When both vWf and CRP were included in the latter multivariate analysis, the RRs were 3.0 (95% CI 1.1 to 7.9) for vWf and 1.3 (95% CI 0.5 to 3.4) for CRP. The association between vWf and risk of cardiovascular mortality was independent of blood group (O versus non-O) and, moreover, similar among subjects with different blood groups. Repeating the analyses for all-cause mortality gave similar results for CRP. For vWf, the RR was 2.0 (95% CI 1.1 to 3.5) after adjustment for all other risk factors. Increased levels of vWf are independently associated with cardiovascular and all-cause mortality in both diabetic and nondiabetic subjects. The association between increased levels of CRP and cardiovascular mortality was partly explained by other risk factors. Mutual adjustment of vWf and CRP did not markedly change the results, favoring the hypothesis that vWf and CRP predict mortality through different pathways.

Relationship Between A1C and Glucose Levels in the General Dutch Population: The New Hoorn Study

OBJECTIVE To investigate the relationship among A1C, fasting plasma glucose (FPG), and 2-h postload plasma glucose in the Dutch general population and to evaluate the results of using A1C for screening and diagnosis of diabetes. RESEARCH DESIGN AND METHODS In 2006–2007, 2,753 participants of the New Hoorn Study, aged 40–65 years, who were randomly selected from the population of Hoorn, the Netherlands, underwent an oral glucose tolerance test (OGTT). Glucose status (normal glucose metabolism [NGM], intermediate hyperglycemia, newly diagnosed diabetes, and known diabetes) was defined by the 2006 World Health Organization criteria. Spearman correlations were used to investigate the agreement between markers of hyperglycemia, and a receiver operating characteristic (ROC) curve was calculated to evaluate the use of A1C to identify newly diagnosed diabetes. RESULTS In the total population, the correlations between fasting plasma glucose and A1C and between 2-h postload plasma glucose and A1C were 0.46 and 0.33, respectively. In patients with known diabetes, these correlations were 0.71 and 0.79. An A1C level of ≥5.8%, representing 12% of the population, had the highest combination of sensitivity (72%) and specificity (91%) for identifying newly diagnosed diabetes. This cutoff point would identify 72% of the patients with newly diagnosed diabetes and include 30% of the individuals with intermediate hyperglycemia. CONCLUSIONS In patients with known diabetes, correlations between glucose and A1C are strong; however, moderate correlations were found in the general population. In addition, based on the diagnostic properties of A1C defined by ROC curve analysis, the advantage of A1C compared with OGTT for the diagnosis of diabetes is limited.

Estimated Glomerular Filtration Rate and Urinary Albumin Excretion Are Independently Associated with Greater Arterial Stiffness: The Hoorn Study

Mild renal insufficiency is a risk factor for cardiovascular disease (CVD). Both a decline in GFR and (micro)albuminuria are associated with greater cardiovascular mortality. In ESRD, arterial stiffness, an important cause of CVD, is known to be greater, but few data exist in individuals with mild renal insufficiency or microalbuminuria. This study investigated the association of impaired renal function expressed as lower GFR or greater urinary albumin excretion with arterial stiffness. In a population-based study in 806 individuals (402 men), mean age 68 yr (range 50 to 87), peripheral arterial stiffness (by compliance and distensibility of the carotid, brachial, and femoral arteries and by the carotid elastic modulus [E(inc)]) and central arterial stiffness (by total systemic arterial compliance, carotid-femoral transit time, and aortic augmentation index) were measured ultrasonically. GFR was estimated (eGFR) by the Modification of Diet in Renal Disease (MDRD) formula. Urinary albumin excretion was expressed as urinary albumin/creatinine ratio (UACR). eGFR was 60.6 +/- 11.1 ml/min per 1.73 m(2). Median UACR was 0.57 mg/mmol (range 0.1 to 26.6). After adjustment for age, mean arterial pressure (MAP), gender, and glucose tolerance status (GTS), each 5-ml/min per 1.73 m(2) lower eGFR was associated with a lower distensibility coefficient of the carotid (regression coefficient beta -0.20 10(-3)/kPa; 95% confidence interval [CI] -0.34 to -0.07 10(-3)/kPa) and brachial artery (-0.15 10(-3)/kPa; 95% CI -0.28 to -0.03 10(-3)/kPa) and a greater carotid E(inc) (0.02 kPa; 95% CI 0.0004 to 0.04 kPa). No statistically significant association was found of eGFR with other arterial stiffness indices. After adjustment for age, MAP, gender, and GTS, a greater UACR (per quartile) was associated with a greater E(inc) (0.03 kPa; 95% CI 0.001 to 0.07 kPa) and a trend to a lower distensibility coefficient (-0.24 10(-3)/kPa; 95% CI -0.49 to 0.02 10(-3)/kPa) of the carotid artery. After adjustment for age, MAP, gender, and GTS, a greater UACR (per quartile) was in addition associated with a shorter carotid-femoral transit time (-1.67 ms; 95% CI -3.24 to -0.10 ms). These associations were not substantially changed by mutual adjustment for eGFR and UACR. In individuals with mild renal insufficiency, both a lower eGFR and a greater albumin excretion, even below levels that are considered to reflect microalbuminuria, are independently associated with greater arterial stiffness. Moreover, these associations were mutually independent. These findings may explain, in part, why eGFR and microalbuminuria are associated with greater risk for CVD and suggest that amelioration of arterial stiffness could be a target of intervention.

Cardiovascular events in type 2 diabetes : comparison with nondiabetic individuals without and with prior cardiovascular disease. 10-year follow-up of the Hoorn Study

AIMSnWe questioned whether prior cardiovascular disease has the same impact on risk of cardiovascular events as type 2 diabetes, and whether this differed between men and women.nnnMETHODS AND RESULTSnTo address these issues we compared the 10-year risk of cardiovascular events among 208 Caucasian individuals with diabetes to that of 2253 Caucasian individuals without diabetes, in a population-based cohort study. Gender significantly modified the association between type 2 diabetes and cardiovascular events (p=0.01). The hazard ratio of cardiovascular events associated with the presence of diabetes was higher in women (adjusted hazard ratio, 1.8; 95% CI, 1.2 to 2.7) than in men (adjusted hazard ratio, 1.3; 0.9 to 2). As compared to men without diabetes but with prior cardiovascular disease, risk of cardiovascular events was significantly lower in men with diabetes but without prior cardiovascular disease (adjusted hazard ratio, 0.5; 0.3 to 0.9). In contrast, this risk was equal in women with diabetes but without prior cardiovascular disease and women without diabetes but with prior cardiovascular disease (adjusted hazard ratio, 1.0; 0.6 to 1.7; P for interaction between gender and diabetes=0.05).nnnCONCLUSIONSnWomen with diabetes but without prior cardiovascular disease have a risk of cardiovascular events that is similar to that of women without diabetes but with prior cardiovascular disease, whereas in men the presence of prior cardiovascular disease conferred a higher risk. These data emphasise the necessity of aggressive treatment of cardiovascular risk factors in women with type 2 diabetes.

Evaluation of the Notification Procedure for Physician-Assisted Death in the Netherlands

BACKGROUNDnIn the Netherlands, a notification procedure for physician-assisted death has been in use since 1991. It requires doctors to report each case to the coroner, who in turn notifies the public prosecutor. Ultimately, the Assembly of Prosecutors General decides whether to prosecute. Although physician-assisted death remains technically illegal, doctors are extremely unlikely to be prosecuted if they comply with the requirements for accepted practice. In 1995, the ministers of health and justice commissioned an evaluation to determine the adequacy of the notification procedure.nnnMETHODSnA random sample of 405 physicians were interviewed. We also interviewed 147 physicians who had reported cases of physician-assisted death and 116 coroners, and we reviewed 353 judicial files of reported cases. In addition, we interviewed 48 public prosecutors and reviewed the minutes of the Assembly of Prosecutors General for 1991 to 1995 and all published court decisions from 1981 through 1995.nnnRESULTSnIn 1995, about 41 percent of all cases of euthanasia and physician-assisted suicide were reported. There were no major differences between reported and unreported cases in terms of the patients characteristics, clinical conditions, or reasons for the action. Most patients had cancer and were described as suffering unbearably and hopelessly. Of the 6324 cases reported during the period from 1991 through 1995, only 13 involved prosecution of the physician. The majority of respondents in the groups interviewed thought that all cases of physician-assisted death should be reviewed, although most doctors thought the review should be performed by other doctors, and there was substantial concern about the burden associated with the reporting procedure.nnnCONCLUSIONSnSubstantial progress in the oversight of physician-assisted death has been achieved in the Netherlands. The reporting procedure could be more streamlined and less threatening.

Endothelial Dysfunction and Low-Grade Inflammation Explain Much of the Excess Cardiovascular Mortality in Individuals With Type 2 Diabetes. The Hoorn Study

Objective—The mechanisms responsible for the increased cardiovascular disease risk that accompanies type 2 diabetes (T2D) remain poorly understood. It is commonly held that endothelial dysfunction and low-grade inflammation can explain, at least in part, why deteriorating glucose tolerance is associated with cardiovascular disease. However, there is no direct evidence for this contention. Methods and Results—In this population-based study (n=631), T2D was cross-sectionally associated with both endothelial dysfunction and low-grade inflammation, whereas impaired glucose metabolism (IGM) was associated only with low-grade inflammation. These findings were independent of other risk factors that accompany T2D or IGM. During a follow-up of 11.7 years (median; range 0.5 to 13.2 years), low-grade inflammation was associated with a greater risk of cardiovascular mortality (hazard ratio, 1.43 [95% CI, 1.17 to 1.77] per 1 SD difference). For endothelial dysfunction, the association with cardiovascular mortality was stronger in diabetic (hazard ratio, 1.87 [95% CI, 1.43 to 2.45]) than in nondiabetic individuals (hazard ratio, 1.23 [95% CI, 0.86 to 1.75]; P interaction=0.06). Finally, T2D-associated endothelial dysfunction and low-grade inflammation explained ≈43% of the increase in cardiovascular mortality risk conferred by T2D. Conclusions—These data emphasize the necessity of randomized controlled trials of strategies that aim to decrease cardiovascular disease risk by improving endothelial function and decreasing low-grade inflammation, especially for T2D patients.