Extraction of response waveforms of heartbeat and blood pressure to swallowing. Using mixed signal processing of time domain and respiratory phase domain

BACKGROUND

Evaluating the accurate responses of the cardiovascular system to external stimuli is important for a deeper understanding of cardiovascular homeostasis. However, the responses should be distorted by the conventional time domain analysis when a frequency of the effect of external stimuli matches that of intrinsic fluctuations.

OBJECTIVES

The purpose of this study is to propose a mixed signal processing of time domain and respiratory phase domain to extract the response waveforms of heartbeat and blood pressure (BP) to external stimuli and to clarify the physiological mechanisms of swallowing effects on the cardiovascular system.

METHODS

Measurements were conducted on 12 healthy humans in the sitting and standing positions, with each subject requested to swallow every 30 s between expiration and inspiration. Waveforms of respiratory sinus arrhythmia (RSA) and respiratory-related BP variations were extracted as functions of the respiratory phase. Then, respiratory effects were subtracted from response waveforms with reference to the respiratory phase in the time domain.

RESULTS

As a result, swallowing induced tachycardia, which peaked within 3 s and recovered within 8 s. Tachycardia was greater in the sitting position than during standing. Furthermore, systolic BP and pulse pressure immediately decreased and diastolic BP increased coincident with the occurrence of tachycardia. Subsequently, systolic BP and pulse pressure recovered faster than the R-R interval.

CONCLUSIONS

We conclude that swallowing-induced tachycardia arises largely from the decrease of vagal activity and the baroreflex would yield fast oscillatory responses in recovery.

The cardio-ankle vascular index and ankle-brachial index in young russians

AIM

A noninvasive approach to assess atherosclerosis in young people is of great concern. The cardio-ankle vascular index (CAVI) and ankle-brachial index (ABI) reflect the arterial conditions, although the CAVI has not fully been studied in Russian populations. This study aimed to determine the CAVI and ABI in young Russians, to compare these findings with those in their Japanese peers and to investigate the lifestyle correlates and genetic associations with the CAVI and ABI in the Russians.

METHODS

In addition to several atherosclerotic parameters and self-reported lifestyle factors, the CAVI and ABI levels were measured in 114 Russians (mean 21 years). Four gene polymorphisms, including cholesteryl ester transfer protein (CETP) Taq1B polymorphism, were typed in some of the subjects.

RESULTS

The Russians exhibited significantly higher CAVI levels compared to their Japanese counterparts (5.87 vs. 5.36; p＜0.05), while the ABI levels were similar between the two populations. In the Russians, the ABI was significantly correlated with the mean blood pressure (r=-0.26) and heart rate (r=-0.43), while the CAVI did not show such correlations. No significant associations existed between lifestyle-related factors and the CAVI or ABI levels. A lower ABI level was found in carriers with the T-allele of CETP Taq1B in the Russians.

CONCLUSIONS

The reference CAVI value can be specified for individual ethnic populations. Our findings suggest that Russians may develop atherosclerosis-related conditions at a younger age compared to Japanese subjects, although this must be verified in additional studies. The possible association between CETP polymorphisms and the ABI deserves further investigation.

Effectiveness of Gatekeepers in Determining the Appropriate Use of Brain MRI/MRA Tests

The purpose of the study is to examine whether, among patients who visited hospitals and underwent brain MRI or MRA scan tests, there was a relationship between the existence of clinically significant abnormal findings and the relevance of primary care physicians' referrals. A case-control study was carried out at six teaching hospitals in Japan. We identified cases with significant abnormal MRI/MRA findings from radiologists' reports based on certain explicit criteria and controls with outpatients who underwent MRI/MRA scans but did not have stroke. We also collected clinical data independently from medical records. The findings of 156 cases and 721 controls were collected for the analysis. A multivariate analysis adjusted by age group, sex, and the number of comorbidity factors showed that those who had visited the hospitals after referral were more likely to have significant abnormal findings in their MRI/MRA scan results (odds ratio [OR] = 1.6, 95% CI: 1.1 to 2.4). The present study suggests that referral from gatekeepers such as primary care physicians is effective in determining the appropriate use of brain MRI/MRA tests for hospital outpatients.

Cardio-Ankle Vascular Index and Its Potential Clinical Implications for Sleep Apnea

Sleep apnea is a prevalent disorder associated with an increased risk of cardiovascular disease (CVD). While arterial stiffness is a surrogate marker for the development of CVD, the cardio-ankle vascular index (CAVI) is a recently developed metric for evaluating arterial stiffness. Clinical studies have shown that the CAVI is higher in patients with the sleep apnea syndrome. In particular, a reduction in the CAVI can clearly be seen during short-term therapy for these patients. Although clinical evidence on sleep apnea using the CAVI is currently limited, the CAVI is expected to be useful for identifying patients with an increased risk of CVD and for monitoring treatment effectiveness in sleep apnea practice.

Effect of baseline HbA1c level on the development of diabetes by lifestyle intervention in primary healthcare settings: insights from subanalysis of the Japan Diabetes Prevention Program

OBJECTIVES

To determine the effects of a lifestyle intervention on the development of type 2 diabetes mellitus (T2DM) among participants with impaired glucose tolerance (IGT), in particular in the subgroup with baseline glycated hemoglobin (HbA1c) levels ≥5.7%, in primary healthcare settings.

DESIGN

Randomized controlled trial.

SETTING

32 healthcare centers in Japan.

PARTICIPANTS

Participants with IGT, aged 30-60 years, were randomly assigned to either an intensive lifestyle intervention group (ILG) or a usual care group (UCG).

INTERVENTIONS

During the initial 6 months, participants in the ILG received four group sessions on healthy lifestyles by public health providers. An individual session was further conducted biannually during the 3 years. Participants in the UCG received usual care such as one group session on healthy lifestyles.

OUTCOME MEASURES

The primary endpoint was the development of T2DM based on an oral glucose tolerance test.

RESULTS

The mean follow-up period was 2.3 years. The annual incidence of T2DM were 2.7 and 5.1/100 person-years of follow-up in the ILG (n=145) and UCG (n=149), respectively. The cumulative incidence of T2DM was significantly lower in the ILG than in the UCG among participants with HbA1c levels ≥5.7% (log-rank=3.52, p=0.06; Breslow=4.05, p=0.04; Tarone-Ware=3.79, p=0.05), while this was not found among participants with HbA1c levels <5.7%.

CONCLUSIONS

Intensive lifestyle intervention in primary healthcare setting is effective in preventing the development of T2DM in IGT participants with HbA1c levels ≥5.7%, relative to those with HbA1c levels <5.7%.

TRIAL REGISTRATION NUMBER

UMIN000003136.

The relationship between gamma-glutamyltransferase (GGT), bilirubin (Bil) and small dense low-density lipoprotein (sdLDL) in asymptomatic subjects attending a clinic for screening dyslipidaemias

INTRODUCTION

Gamma-glutamyltransferase (GGT), bilirubin (Bil) and small dense low-density lipoprotein (sdLDL) particles are each known to be risk markers for cardiometabolic diseases which are characterised by oxidative stress conditions. These markers are connected with the oxidative milieu; however, the association between GGT, Bil, and sdLDL has been hardly examined. This hospital-based study investigated the association between GGT and sdLDL, as well as the association between Bil and sdLDL, in asymptomatic subjects.

MATERIALS AND METHODS

Cardiometabolic variables, GGT, Bil and the mean LDL particle size were measured in 100 asymptomatic subjects attending a clinic for screening dyslipidaemias (36 men and 64 women, mean age 64 years). Correlation analyses of the association between the mean LDL particle size and other variables, such as GGT and Bil, were performed.

RESULTS

The mean (standard deviation) levels of GGT, Bil, and the mean LDL particle size were found to be 21.7 (8.3) IU/L, 14.0 (4.3) μmol/L, and 26.7 (0.6) nm, respectively. An univariate correlation test showed both a significant inverse correlation between the mean LDL particle size and GGT (r = - 0.33, P <0.01) and a significant positive correlation between the mean LDL particle size and Bil (r = 0.32, P <0.01). A multiple regression analysis revealed similarly significant results of their correlations, independent of the other cardiometabolic variables.

CONCLUSION

These results suggest that the correlation of GGT and sdLDL, as well as that of Bil and sdLDL, may be cooperatively associated with cardiometabolic processes. Further research is warranted in order to confirm the observed association.

Prognostication based on the change in the palliative prognostic index for patients with terminal cancer

CONTEXT

The use of the Palliative Prognostic Index (PPI) in relation to the clinical time course has not yet been established.

OBJECTIVES

To investigate the association between the changes in the PPI over time and the survival of terminal cancer patients in a palliative care unit (PCU).

METHODS

This retrospective cohort study analyzed data from 374 terminal cancer patients who were admitted to the PCU of a university hospital in Japan. Clinical data, such as age, gender, body mass index, vital signs, initial PPI, and subsequent PPI, were collected from the medical records. The PPI change per day (ΔPPI) was calculated using the initial PPI at admission and the one after five to seven days. The factors associated with death within three weeks were identified using Cox proportional hazards model analysis.

RESULTS

After their admission to the PCU, 147 (39.3%) patients were deceased within three weeks. The multivariate-adjusted analysis showed that body temperature (hazard ratio [HR] 0.7; 95% CI 0.5, 1.0), initial PPI (HR 1.3; 95% CI 1.2, 1.4), and ΔPPI (HR 6.6; 95% CI 4.9, 9.0) were significantly and independently associated with death within three weeks. In the subanalysis, the ΔPPI was significantly associated with death within three weeks in the group with initial PPI ≤ 4 (HR 9.3; 95% CI 5.8, 15.0), 4 < initial PPI ≤ 6 (HR 14.4; 95% CI 5.7, 36.2), and initial PPI > 6 (HR 9.0; 95% CI 4.1, 20.0).

CONCLUSION

Our data suggest that the ΔPPI may be useful for predicting the survival of terminally ill cancer patients.

Equol producers can have low leptin levels among prediabetic and diabetic females

OBJECTIVES

Soy isoflavones have received great attention for their beneficial effects on health and disease, i.e., in patients with diabetes. Equol is a biologically active isoflavone-related metabolite with interindividual differences in its production. The current study investigated the relationship between an equol-producing state and the levels of adipocytokine markers in a prediabetic and diabetic population.

SUBJECTS AND METHODS

A total of 79 subjects (34 males/45 females) in a prediabetic or diabetic state recruited from the general population were examined regarding their ability to produce equol using urine samples. Clinical data, such as age, smoking as well as anthropometric and biochemical variables, including body mass index (BMI), lipids, insulin, glucose, hemoglobin A1c, leptin and adiponectin, were recorded.

RESULTS

Equol producers exhibited lower leptin and leptin/BMI than non-producers among females. Simple correlation tests and stepwise multiple regression analyses revealed a significant inverse correlation between the leptin/BMI and equol-production. This relationship was not found in males.

CONCLUSIONS

Female equol producers can have favorable metabolic traits in relation to leptin metabolism in this population. Further studies are needed to confirm these results.

Evidence for the presence of active paraoxonase 1 in small-dense low-density lipoprotein

AIM

We have recently demonstrated the quick ex vivo transfer of paraoxonase 1 (PON1) activity from high-density lipoprotein (HDL) to small, dense low-density lipoprotein (sdLDL). We set out to assess whether sdLDL contains active PON1 in vivo.

METHODS

We conducted a nested case-control, proof of principle study with the Japanese healthy subjects with normal lipids (n = 23) and age and gender-paired dyslipidemic subjects (n = 17). Lipid panels, lactonase and arylesterase assays, and PON1 zymogram in the LDL and HDL subclasses were assessed.

RESULTS

PON1 specific activity in the high-molecular weight lipoprotein fraction corresponding to LDL migration was found in 48% of normo and in 29% of dyslipidemic Japanese subjects. This band co-localizes with apoB100 and not Lp(a) and displays a lower molecular mass than the bulk of LDL.

CONCLUSION

We provide evidence, for the first time, that native sdLDL contains up to 4% of the total PON1 activity in the serum of up to 48% of the Japanese subjects. Could the PON1-containing sdLDL represent a set of particles with a defense mechanism from oxidation and therefore its levels actually prove to be atheroprotective? If further studies confirm this contention, a zymogram of PON1 in LDL subclasses could be a functional assay that complements the current methods that only inform on the size and lipid concentration of these particles.

[Satisfaction with hospital care among diabetic outpatients and its associated factors. Secondary use of official statistics]

OBJECTIVES

Generalizable data on current satisfaction levels are required to establish a scientific basis for the political advancement of measures to improve satisfaction with hospital care among patients with diabetes. The present study made secondary use of existing official statistics in order to demonstrate the range of satisfaction levels with hospital care among diabetic outpatients and to closely examine related factors.

METHODS

Data sets that consolidated the Patient Survey, the Survey of Medical Care Institutions, and the Patient Behavior Survey (all from 2008) were created. Shared medical institution survey reference numbers were used to consolidate the data from the Patient Survey and the Survey of Medical Care Institutions, and in addition, sex and date of birth were used to consolidate the Patient Behavior Survey data. The range of satisfaction levels with hospital care among diabetic outpatients was investigated along with any relationship with the following potentially related factors: visitation status (first or repeat examination); waiting time until examination; examination duration; care-seeking status (any use of other medical facilities, etc.); diabetic complications; other complications; coverage under the Public Assistance Act; smoking cessation outpatient services; hospitals that specialized in treating diabetes (metabolic medicine); medical care on Saturday, Sunday, and public holidays; and provision of health checkups.

RESULTS

Overall, 62.3% of diabetic outpatients were either fairly or extremely satisfied with their hospital care, whereas 5.6% expressed dissatisfaction. Satisfaction levels with hospital care were found to be significantly related to visitation status, waiting time until examination, examination duration, care-seeking status, and Saturday medical care. Multivariate analysis with the factors demonstrated to be significantly related to satisfaction revealed significant relationships between high satisfaction levels and repeat examinations, short waiting times, no use of any other medical facilities, and long examinations.

CONCLUSION

Consolidating official statistics from multiple sources indicated the range of satisfaction levels with hospital care among diabetic outpatients and facilitated the clarification of factors affecting satisfaction. Reducing waiting times and ensuring sufficient time spent on examinations are important for increasing satisfaction levels with hospital care among patients with diabetes. It is hoped that official statistics can be further applied to many future public health policy studies.

Accumulation and absorption of serum amyloid A and apolipoprotein E fragments in the course of AA amyloidosis: a study in a mouse model

Reactive AA amyloidosis develops secondary to chronic inflammatory disorders. Serum amyloid A protein (SAA) and its degradation products, named AAs, are the main components of amyloid deposits, while apolipoprotein E (apoE) fragments are the minor components. To further understand the molecular mechanism of AA amyloidosis, we examined SAA/AAs moieties and apoE in the spleen and plasma throughout the amyloid-generating and amyloid-absorbing phases in a mouse model. SAA and four AA species (8.5kDa, 7.8kDa, 7.0kDa, and 6.2kDa) were detected in the spleen. SAA and the 8.5 kDa and 7.8 kDa AAs were prominent in the acute phase, whereas the 7.0kDa AA, the second smallest AA corresponding to the most common form in the human disease, was prominent in the chronic phase. These results indicate that the higher molecular weight species first constituted the fibril, followed by the 7.0kDa species, which were finally absorbed. ApoE was a component of the amyloid deposits at a degradation size from the beginning and was absorbed without being converted to another size. Degradation products, either from SAA or apoE, did not appear in the plasma during the course of the disease. A more detailed understanding of the moieties of amyloid-related peptides may help in the development of a method that can indicate the disease activity of AA amyloidosis.

Eicosapentaenoic acid/arachidonic acid ratio and smoking status in elderly patients with type 2 diabetes mellitus

BACKGROUND

A low ratio of eicosapentaenoic acid (EPA)/arachidonic acid (AA) is considered a risk factor for cardiovascular disease. Smoking is also a risk factor for cardiovascular disease even in an elderly population. This study investigated the relationship between EPA/AA ratio and smoking status among elderly patients with type 2 diabetes mellitus (T2DM).

FINDINGS

A total of 188 elderly patients with T2DM (men/women, 114/74; mean age, 65.0 ± 7.5 years) were studied in terms of their smoking status, diabetic conditions, and blood data, including EPA and AA. Current smokers showed a lower EPA/AA ratio than non-smokers (current smokers: 0.29, n = 49; non-smokers: 0.39, n = 139, p < 0.01). This relationship remained significant after adjusting for multiple variables.

CONCLUSIONS

Smoking may affect the EPA/AA ratio among elderly patients with T2DM, suggesting a possible mechanism of cardiovascular disease development and indicating the importance of smoking secession in such patients.

Thyroid ultrasound findings in children from three Japanese prefectures: Aomori, Yamanashi and Nagasaki

Due to the likelihood of physical and mental health impacts following the unprecedented accident at the Fukushima Dai-ichi Nuclear Power Plant, the Fukushima prefectural government decided to conduct the Fukushima Health Management Survey to assist in the long-term health management of residents. This included thyroid ultrasound examination for all children in Fukushima. For appropriate evaluation of ultrasound screening of the thyroid, it is important to understand its reference data of thyroid findings in children in general. In order to analyze the frequencies of specific thyroid findings, we conducted ultrasound screening of the thyroid by the same procedures as used in Fukushima in 4,365 children, aged 3 to 18 years, from three Japanese prefectures. Overall, thyroid cysts were identified in 56.88% and thyroid nodules in 1.65% of the participants. Thyroid cysts and nodules with a maximum diameter of more than 5 mm were identified in 4.58% and 1.01%, respectively, and age-adjusted prevalences were 3.82% and 0.99%, respectively. Although the prevalence of cysts and nodules varied among the examination areas, no significant differences were observed among the three examination areas in the prevalence of cysts and nodules with a maximum diameter of more than 5 mm. Also, the prevalence of thyroid cysts and nodules, especially those with a maximum diameter of more than 5 mm, significantly increased with age, and showed a female predominance. We also identified ectopic thymus (1.95%), diffuse goiter (1.40%), ultimobranchial body (0.73%), lymph node swelling (0.21%) and thyroid agenesis (0.05%). This is the first ultrasound description of the age-adjusted prevalence of thyroid cysts and nodules, or of the prevalence of abnormalities other than cysts and nodules, such as ectopic thymus, in relation to age, in the general Japanese child population. We contend that this can provide relevant information for the Fukushima Health Management Survey and future population studies.

The -3826 A → G variant of the uncoupling protein-1 gene diminishes thermogenesis during acute cold exposure in healthy children

SUMMARY

Uncoupling protein-1 (UCP1) activity in brown adipose tissue increases energy expenditure, and contributes to diet-induced or cold-induced thermogenesis. We previously reported that children with -3826 A → G nucleotide variant of the UCP1 gene had lowered postprandial thermogenesis in response to a high-fat meal. In this study, we investigated whether the UCP1 polymorphism was associated with cold-induced thermogenesis in healthy children. Resting energy expenditure was measured in 19 children (6-10 years) by indirect calorimetry for 30 min under thermoneutral (25 °C) or cold conditions (10 °C) in an environmental chamber. The activity of autonomic nervous system (ANS) was assessed by power spectral analysis of heart rate variability (HRV). Samples of saliva were collected for cortisol determination at the end of the experimental session. Each experiment was performed on 2 consecutive days. Children were genotyped for the UCP1 polymorphism with a PCR-restriction fragment length analysis using buccal samples. During cold exposure, total power of the HRV, an index of the overall ANS activity, as well as the salivary cortisol concentration significantly increased in the children with homozygous (GG) for the UCP1 polymorphism while only cortisol response was found in the carriers of the wild-type (AA) and heterozygous (AG) alleles; however, the GG allele group showed a lower cold-induced thermogenesis compared to the AA + AG group. In conclusion, despite cold-induced autonomic stimulation, the GG allele carriers have a reduced capacity for thermogenesis in response to acute cold exposure, suggesting that such reduced UCP1-linked thermogenesis may have adverse effects on the regulation of body weight.:

Effects of a year-long pedometer-based walking program on cardiovascular disease risk factors in active older people

We assessed the relationship between the number of daily steps and changes in cardiovascular disease (CVD) risk factors in a year-long pedometer-based walking program for physically active older people. A total of 36 physically active older people (68.3 ± 5.8 years) completed this 59-week program. The CVD risk parameters were measured at baseline and at weeks 21 and 59. The mean number of steps increased by week 21 and was maintained at week 59 (approximately 10 000 steps, increase in 1500 steps from the baseline; P < .05). Following a significant reduction in body mass index at week 21, systolic blood pressure levels were significantly reduced, and high-density lipoprotein cholesterol levels were significantly increased at week 59 (P < .05). In summary, even active older people can achieve further protection against CVD risks by minor, but sustained, physical activity using pedometers for a period of more than 1 year.

Mortality among Japanese with a history of Kawasaki disease: results at the end of 2009

BACKGROUND

The long-term outcomes of Kawasaki disease (KD) are unknown.

METHODS

Fifty-two collaborating hospitals collected data on all patients who had received a new definite diagnosis of KD between July 1982 and December 1992. Patients were followed until December 31, 2009 or death. Standardized mortality ratios (SMRs) were calculated based on Japanese vital statistics data.

RESULTS

Of the 6576 patients enrolled, 46 (35 males and 11 females) died (SMR: 1.00; 95% CI: 0.73-1.34). Among persons without cardiac sequelae, SMRs were not high after the acute phase of KD (SMR: 0.65; 95% CI: 0.41-0.96). Among persons with cardiac sequelae, 13 males and 1 female died during the observation period (SMR: 1.86; 95% CI: 1.02-3.13).

CONCLUSIONS

In this cohort, the mortality rate among Japanese with cardiac sequelae due to KD was significantly higher than that of the general population. In contrast, the rates for males and females without sequelae were not elevated.

High-density lipoprotein and prostate cancer: an overview

Prostate cancer is a common disease in modern, developed societies and has a high incidence and mortality. High-density lipoprotein cholesterol (HDL-C) has recently received much attention as a possible risk marker of prostate cancer development and prognosis. In the present article, we summarized findings from epidemiologic studies of the association between HDL-C and prostate cancer. Low HDL-C level was found to be a risk and prognostic factor of prostate cancer in several epidemiologic studies, although the overall linkage between HDL and prostate cancer has not been definitively established. The mechanisms for this association remain uncertain; however, limited data from experimental studies imply a possible role of HDL in the pathophysiology of prostate cancer. More epidemiologic research, in combination with experimental studies, is needed in this field.

Circulating soluble receptor for advanced glycation end products is inversely correlated to oxidized low-density lipoproteins in asymptomatic subjects

OBJECTIVE

There is growing evidence that circulating soluble receptor for advanced glycation end products (sRAGE) exerts antiatherogenic effects as a decoy receptor that abolishes RAGE signalling. A previous study reported that oxidized low-density lipoprotein (oxLDL) can be one of the RAGE ligands. The present cross-sectional study investigated the clinical association between sRAGE and oxLDL in humans.

METHODS

Serum levels of the conventional atherosclerotic risk factors, sRAGE and malondialdehyde-modified low-density lipoprotein (MDA-LDL) were analysed in asymptomatic subjects; MDA-LDL was measured as a biomarker of oxLDL.

RESULTS

Mean serum levels of sRAGE and MDA-LDL were 1101 ng/l and 57.6 IU/l, respectively, in 33 subjects of mean age 65 years. Simple linear regression analysis showed a significant inverse correlation between sRAGE and MDA-LDL. Stepwise multiple linear regression analysis confirmed MDA-LDL to be independently, significantly and inversely correlated with sRAGE.

CONCLUSIONS

An independent, significant and inverse correlation was shown to exist between circulating levels of sRAGE and oxLDL (MDA-LDL), which suggests that part of the antiatherosclerotic effects of sRAGE may be related to oxLDL quenching.

Heterogeneous properties of intermediate- and low-density lipoprotein subpopulations

OBJECTIVE

Intermediate-density lipoprotein (IDL) and low-density lipoprotein (LDL) consist of heterogeneous particles whose subpopulations may have different atherogenic characteristics. This study investigated the associations between these subpopulations and other lipids, lipoproteins and atherosclerosis-related markers.

DESIGN AND METHODS

A total of 416 subjects (124 males and 292 females, mean age: 50.8 years) were enrolled in this study. Using polyacrylamide gel electrophoresis, serum lipoproteins were separated according to their specific electrophoretic mobility based on particle size. The IDL particles were separated into three midbands (MID-A to C), and the LDL particles were separated into seven subfractions (LDL1 to 7).

RESULTS

MID-B, MID-C, LDL2 and LDL3 to 6 (as a small LDL fraction) were significantly and positively correlated with very LDL (VLDL), while MID-A and LDL1 were significantly and inversely correlated with VLDL. MID-A and LDL1 were significantly and positively correlated with high-density lipoprotein (HDL). The correlation patterns between MID-A or LDL1 and triglycerides, apolipoprotein A-I, glucose, the insulin resistance index, creatinine and the mean LDL particle size had similar trends to those between HDL and these parameters.

CONCLUSIONS

The respective subpopulations of IDL and LDL particles can vary in their ability to predict cardiovascular disease risks. These variations may partially explain why quantitative assessments using LDL-cholesterol concentrations, as typically performed in conventional practice, are not perfect predictors of cardiovascular disease. Further studies are required to determine the clinical relevance of analyzing the IDL and LDL subpopulations.