High-density lipoprotein cholesterol, a protective or a risk factor for developing coronary heart disease? Tehran Lipid and Glucose Study

The association of menopause with cardiometabolic disease risk factors in low- and middle-income countries: a systematic review and meta-analyses

IMPORTANCE

Menopause is an integral part of women's health, and studies in high-income countries have shown an increase in cardiometabolic disease (CMD) risk factors in postmenopausal compared with premenopausal women. However, to date, no study has combined and assessed such studies across low- and middle-income countries. This would better inform early monitoring and intervention strategies for reducing CMD risk factor levels in midlife women in these regions.

OBJECTIVE

This study aimed to evaluate evidence from the literature on differences in CMD risk factors between premenopausal and postmenopausal midlife women living in low- and middle-income countries.

EVIDENCE REVIEW

A systematic review with meta-analysis of original articles of all study designs from the databases PubMed, PubMed Central, Scopus, and ISI Web of Science was conducted from conception until April 24, 2023. Studies that met the inclusion criteria were included in the analysis. Quality assessment of the articles was done using the Newcastle-Ottawa Scale, adapted for each study design. The study protocol was registered with the International Prospective Register of Systematic Reviews and adheres to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis. For the meta-analysis, fixed-effects models were used to pool the odds ratios (OR), as measures of association.

FINDINGS

Our search identified 4,849 relevant articles: 44 for the systematic review and 16 for the meta-analysis, in accordance with our inclusion criteria. Compared with premenopausal women, the postmenopausal stage was associated with metabolic syndrome (OR, 1.18 [95% CI, 1.11-1.27]), high waist-to-hip ratio (OR, 1.22 [95% CI, 1.12-1.32]), hypertension (OR, 1.10 [95% CI, 1.04-1.16]), elevated triglycerides (OR, 1.16 [95% CI, 1.11-1.21]), and elevated plasma glucose (OR, 1.21 [95% CI, 1.15-1.28]).

CONCLUSIONS AND RELEVANCE

This study confirmed that CMD risk factors are present at higher levels in postmenopausal than premenopausal women. This demonstrates an urgent need for public health policies that focus on early monitoring and interventions targeted at reducing CMD risk and related adverse outcomes in midlife women in these nations.

Cardiovascular Disease in Women: Does Menopause Matter?

It is known that the menopause transition (MT) is a complex period during a woman's life, but there has been ongoing debate on whether the increase in cardiovascular disease (CVD) during midlife is due to chronological aging or ovarian aging. The purpose of this review is to summarize the recent findings on the role of ovarian aging versus chronological aging on cardiovascular disease (CVD) outcomes and its risk factors in women. Recent data from longitudinal studies have shown that menopause-related factors, such as earlier age at menopause and surgical menopause are associated with higher CVD outcomes. The MT is also associated with detrimental changes in vascular health as well as cardiometabolic risk factors including body composition, visceral fat accumulation, lipids/lipoproteins, blood pressure and the metabolic syndrome. The robust evidence from recent research indicating increases in CVD risk over the MT beyond aging call for immediate efforts to rise awareness among women and their health care providers of CVD risk acceleration accompanying the MT. Efforts should also be directed toward developing and testing novel preventive approaches that target women during this time period to counteract the expected increase in CVD risk.

Frequency of Metabolic Syndrome and Study of Anthropometric, Clinical and Biological Characteristics in Peri- and Postmenopausal Women in the City of Ksar El Kebir (Northern Morocco)

This study aimed to determine the frequency of metabolic syndrome and to identify its predictive factors in peri- and post-menopausal women in the city of Ksar El Kebir, in northern Morocco. A total of 373 peri- and post-menopausal women between 45 and 64 years old participated in the study. Metabolic syndrome was diagnosed according to the National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III) definition. Body mass index (BMI) was calculated to assess the degree of obesity in women; anthropometric, clinical and biological parameters were collected during interviews. The mean ages of peri- and postmenopausal women were 48.84 ± 2.4 years and 56.65 ± 4.29 years, respectively. Postmenopausal women had higher means of anthropometric and biological parameters than peri-menopausal women. We also noted a predominance of metabolic syndrome in postmenopausal women (n = 158) compared to peri-menopausal women (n = 81). Waist circumference was the predominant marker in the subjects studied, whereas triglycerides were the lower marker. In the overall population, the incidence of metabolic syndrome and its associated factors were higher in postmenopausal women than in peri-menopausal women, from which it can be concluded that post menopause may be a predictor of metabolic syndrome.

Dyslipidemia and Its Components Across Body Mass Index Levels Among Type II Diabetic Patients in the West of Iran

Background:

The combination of dyslipidemia, obesity, and hyperglycemia can accelerate the progression to cardiovascular disease. Therefore, this study aimed to investigate dyslipidemia and its components across body mass index (BMI) levels among type II diabetic patients.

Methods:

The data for this cross-sectional study were extracted from the records of diabetic patients during 2014 to 2015. About 2,300 diabetic patients had been registered, and finally, the records of 2,110 patients which were fully completed were investigated. Dyslipidemia was defined based on the NCEP/ATP III classification of lipid profile. In order to investigate about nonlinear relationship between BMI and dyslipidemia, and its components, restricted cubic spline method was used.

Results:

The median age of patients was 55 (IQR = 14) years. 61.11% was females. The median of BMI, triglyceride, cholesterol, HDL-Chol, and LDL-Chol were 28.3 kg/m², 167, 193, 41, and 110 mg/dL in patients, respectively. The prevalence of dyslipidemia was 91.29% (95% CI: 90.05–92.54). Being overweight, diabetic patients were associated with an increased risk of dyslipidemia (OR = 1.87–2.78), hypertriglyceridemia (OR = 1.64; 95% CI: 1.29–2.09), and hypo-HDL (OR = 1.55; 95% CI: 1.20–2.01). Similarly, obesity also increased the risk of dyslipidemia (OR = 1.94; 95% CI: 1.28–2.95), hypertriglyceridemia (OR = 1.66; 95% CI: 1.29–2.12), and hypo-HDL (OR = 1.86; 95% CI: 1.41–2.43). The nonlinear dose–response relationship was associated with a significant increase then decrease in the risk of dyslipidemia, hypertriglyceridemia, and hypo-HDL in men and women as per 1 kg/m² increase in BMI.

Conclusions:

With regards to the result, we know that there is no linear relationship between lipid profiles and BMI, the bell-shape association between dyslipidemia, hypertriglyceridemia, and hypo-HDL needs to be further investigated in both diabetic and general population in men and women separately. In addition, for public health section, an appropriate intervention is of most important priorities.

Effect of Chinese herbal medicine on serum lipids in postmenopausal women with mild dyslipidemia: a randomized, placebo-controlled clinical trial

OBJECTIVE

Previous studies have shown the association between menopause and dyslipidemia. This study was aimed to evaluate the effect of Chinese herbal medicine, tonifying kidney and descending turbidity (TKDT) granule, on serum lipid profiles in postmenopausal women with dyslipidemia.

METHODS

A double-blind randomized, placebo-controlled trial was conducted among 104 postmenopausal Chinese women with mild dyslipidemia. Participants were randomized into treatment group (n = 53) and control group (n = 51). The participants in the treatment group received TKDT granule once per day for 24 weeks, whereas the control group received placebo in the same manner. All participants were subjected to healthy lifestyle during the study. Serum lipid profiles, body weight, waist circumference, and safety indicators were measured both at baseline and 24 weeks after admission.

RESULTS

Compared with placebo, significant improvements in total cholesterol, low-density lipoprotein cholesterol, apolipoprotein-B (Apo-B), weight, and waist circumference in the TKDT group (P < 0.05) were observed after 24 weeks of treatment. Total cholesterol, low-density lipoprotein cholesterol, and Apo-B were decreased by 0.84 (0.77) mmol/L, 0.72 (0.77) mmol/L, and 0.12 (0.27) mmol/L, mean ± SD respectively. The weight, waist circumference, and body mass index were decreased by 4.07 (3.01) kg, 3.10 (2.95) cm, 1.60 (1.13), respectively. There were no significant differences in triglycerides, high-density lipoprotein cholesterol, and Apo-A between the two groups. Seven participants in the treatment group and six participants in the placebo group had mild or moderate adverse reactions.

CONCLUSION

TKDT granule improved the lipid profile and reduced the related metabolic abnormalities in postmenopausal women with mild dyslipidemia based on lifestyle changes.

Serum Lipids and Cardiovascular Disease Mortality in Iranian Population: Joint Modeling of Longitudinal and Survival Data in Tehran Lipid and Glucose Study (TLGS) Cohort

Background:

Lipid abnormalities are major risk factors of death from cardiovascular disease (CVD). As well as, lipid markers are time-dependent covariates that change with aging. Previous cohort studies have only investigated baseline measurements of lipid markers on CVD mortality.

Materials and Methods:

The study sample consisted of 4,148 individuals aged over 40 years. Total cholesterol (TC), LDL-cholesterol (LDL-C), and HDL-cholesterol (HDL-C) were measured in five phases. A joint model analysis was used to investigate the association between each longitudinal lipid markers and CVD mortality in men, women and pooled sample. All analysis was performed using the survival and joint modeling packages in R 3.3.3.

Results:

Totally, 233 CVD deaths occurred during a median follow-up of 12.4 years. For men, CVD mortality increased by 28% (confidence interval [CI]: 14%,44%) for a 10% increased in TC. For women, CVD mortality increased by 43% (CI: 22%, 68%) and 21% (CI:7%, 37%) for 10 % increase in TC and LDL-C and decreased by 18% (CI:7%, 27%) for a 10% increase in HDL-C.

Conclusion:

Association of lipid markers with CVD mortality is different in men and women, such that high levels of TC and LDL-C and low levels of HDL-C are risk factors of CVD mortality in women, but only TC is a risk factor of CVD mortality in men.

Serum Lipids During 20 Years in the Tehran Lipid and Glucose Study: Prevalence, Trends and Impact on Non-Communicable Diseases

CONTEXT

Dyslipidemia, including elevated serum total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), and triglycerides (TG), and low high density lipoprotein cholesterol (HDL-C) is a major modifiable risk factor for non-communicable diseases (NCDs). This review summarizes many of the key findings on lipid measures in the Tehran lipid and glucose study (TLGS), a large scale community-based study with an approximately two decade follow-up.

EVIDENCE ACQUISITION

A systematic literature search was conducted using PubMed, Scopus, Web of Science databases, and the library of the Research Institute for Endocrine Sciences, using the following keywords: Lipid measures, lipid ratios, lipid profile, dyslipidemia, and "Tehran lipid and glucose study". Articles were categorized based on fields of prevalence, trends, and impact of lipid profile on incident NCDs and mortality.

RESULTS

Between 1999 - 2001, the prevalence of high risk lipids ranged from 14% (low HDL-C) to 17% (high LDL-C) among adolescents, although among adults the lowest and highest prevalence were observed for low HDL-C (19%) and high TG (28%). Despite favorable trends for lipid parameters among adolescents, adults, and the elderly population, a considerable number of diabetic individuals, failed to achieve the optimum level of serum lipids. During follow-up, consumption of lipid-lowering drugs increased from 1.5 to 9.0% and 3.7 to 11.4% among adult men and women, respectively. The association between different lipid parameters and related ratios for incident type 2 diabetes (T2D), hypertension, metabolic syndrome and cardiovascular diseases differed between genders. Interestingly, each 1-unit increase in TC/HDL-C increased risk of hypertension among women (odds ratio (OR): 1.19, 95% confidence interval (CI): 1.00 - 1.27) and T2D among men (OR: 1.27, 95% CI: 1.06 - 1.51). Moreover, TC, LDL-C, non-HDL-C, Ln-TG, TC/HDL-C, and Ln-TG/HDL were inversely associated with non-cardiovascular mortality.

CONCLUSIONS

Despite high prevalence of high risk lipid profiles among the TLGS population at baseline, favorable trends were observed in levels of all lipid components, which might be attributable to increased consumption of lipid-lowering medications and improvement in the general knowledge of Iranians regarding limited consumption of hydrogenated oil. Considering the impact of lipid profiles on incident NCDs, more attention should be paid to at-risk groups for screening and treatment purposes.

HDL and the menopause

PURPOSE OF REVIEW

To summarize recent provocative findings on conventional and novel metrics of HDL including HDL-C, HDL subclasses and HDL cholesterol efflux capacity as related to menopause.

RECENT FINDINGS

Pattern of menopause-related changes in HDL-C are not consistent, suggesting a complex relationship between HDL and menopause. Growing body of literature indicates that higher levels of HDL-C may not be consistently cardio-protective in midlife women, suggesting a potential change in other metrics of HDL that could not be captured by the static metric HDL-C. It is also possible that higher HDL-C at certain conditions could be a marker of HDL metabolism dysfunctionality. Significant alterations in other metrics of HDL have been reported after menopause and found to be related to estradiol.

SUMMARY

The impact of changes in novel metrics of HDL over the menopausal transition on cardiovascular disease (CVD) risk later in life is not clear in women. Much of our understanding of how the menopausal transition may impact HDL metrics comes from cross-sectional studies. Future longitudinal studies are needed to evaluate other metrics of HDL shown to better reflect the cardio-protective capacities of HDL, so that the complex association of menopause, HDL and CVD risk could be characterized.

Divergent pathway of lipid profile components for cardiovascular disease and mortality events: Results of over a decade follow-up among Iranian population

BACKGROUND

Data regarding the impact of different lipid measures on cardiovascular diseases (CVD) and mortality events is not consistent. We aimed to evaluate the relationship between different lipid parameters and incident CVD and mortality events in an Iranian population over a median follow-up of 11.9 years.

METHODS

The study was conducted on 2532 men and 2986 women aged ≥ 40 years. Multivariate adjusted hazard ratios (HRs), using age as time scale, were calculated for every 1 standard deviation (SD) increase in total cholesterol (TC), logarithm-transformed triglycerides (ln-TGs), low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), non-HDL-C, TC/HDL-C and ln-TGs/HDL-C. Covariates included gender (female as reference), body mass index, education status, low physical activity, smoking, blood pressure status (normotension, prehypertension and hypertension), glucose tolerance status (normal glucose tolerance, prediabetes and diabetes) and lipid lowering drugs. The same analyses were also repeated for tertiles of all lipid measures. Considering the absence of interaction between gender and lipid parameters, we used a sex-adjusted analysis. For analyses of mortality events, prevalent CVD was adjusted as well (All p for interactions > 0.1).

RESULTS

A total of 789 new CVD events, 279 cardiovascular (CV) and 270 non-CV deaths occurred. In multivariate analysis, all lipid measures except HDL-C showed significant risk for new CVD events with HRs ranged from 1.14 to 1.27 for ln-TGs/HDL-C and LDL-C, respectively (all p-values ≤ 0.001). Considering CV mortality, there were significant positive associations between TC, LDL-C, non-HDL-C, TC/HDL-C and CV mortality events in sex-adjusted analysis; however after multivariate analysis, these associations attenuated and reached to null. Applying lipid measures as categorical variables, only TC displayed a positive association with CV mortality in multivariate analysis [TC ≥ 6.14 mmol/L: HR 1.43 (1.04-1.98)]. In multivariate analysis, there were negative significant associations between all lipid measures except HDL-C and non-CV mortality; every 1-SD increase in TC, LDL-C, non-HDL-C, ln-TGs ,TC/HDL-C and ln-TGs/HDL-C was associated with 24, 25, 27, 19, 23 and 17 % decreased risk in non-CV mortality (all p-values ≤ 0.01).

CONCLUSIONS

These findings indicate divergent associations of TC, LDL-C, non-HDL-C, TC/HDL-C, TGs and TGs/HDL-C with CVD vs non-CV mortality, demonstrating a higher risk for the former and lower risk for the latter.

Clinical implications of the IMPROVE-IT trial in the light of current and future lipid-lowering treatment options

INTRODUCTION

A residual risk of morbidity and mortality from cardiovascular (CV) disease remains despite statin therapy. This situation has generated an interest in finding novel approaches of combining statins with other lipid-lowering agents, or finding new lipid and non-lipid targets, such as triglycerides, high-density lipoprotein cholesterol (HDL-C), non-HDL-C, proprotein convertase subtilisin/kexin type 9 (PCSK9) gene, cholesterol ester transfer protein (CETP), lipoprotein (a), fibrinogen or C-reactive protein.

AREAS COVERED

The recent results from the IMProved Reduction of Outcomes: Vytorin Efficacy International Trial (IMPROVE-IT) demonstrated an incremental clinical benefit when ezetimibe, a non-statin agent, was added to simvastatin therapy.

EXPERT OPINION

The results from IMPROVE-IT revalidated the concept that low-density lipoprotein cholesterol (LDL-C) levels are a clinically relevant treatment goal. This trial also suggested that further decrease of LDL-C levels (53 vs. 70 mg/dl; 1.4 vs. 1.8 mmol/l) was more beneficial in lowering CV events. This "even lower is even better" evidence for LDL-C levels may influence future guidelines and the use of new drugs. Furthermore, these findings make ezetimibe a more realistic option to treat patients with statin intolerance or those who cannot achieve LDL-C targets with statin monotherapy.