Polymorphisms in the IRS‐1 and PPAR-γ genes and their association with polycystic ovary syndrome among South Indian women

The Role of Peroxisome Proliferator-Activated Receptors in Polycystic Ovary Syndrome

Polycystic ovary syndrome (PCOS) constitutes the most common endocrine disorder in women of reproductive age. Patients usually suffer from severe menstrual irregularities, skin conditions, and insulin resistance-associated health conditions. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptor proteins that regulate gene expression. In order to investigate the role of PPARs in the pathophysiology of PCOS, we conducted a literature review using the MEDLINE and LIVIVO databases and were able to identify 74 relevant studies published between 2003 and 2023. Different study groups reached contradictory conclusions in terms of PPAR expression in PCOS. Interestingly, numerous natural agents were found to represent a novel, potent anti-PCOS treatment alternatives. In conclusion, PPARs seem to play a significant role in PCOS.

Insulin Receptor Substrate 1 Gly972Arg (rs1801278) Polymorphism Is Associated with Obesity and Insulin Resistance in Kashmiri Women with Polycystic Ovary Syndrome

Background: Polycystic ovary syndrome (PCOS) is commonly associated with metabolic abnormalities such as hyperinsulinemia, insulin resistance and obesity. The genetic variants of genes regulating insulin action, expression and regulation are suggested as possible factors involved in development and severity of clinical manifestations in PCOS. Aim: We investigated whether IRS-1Gly972Arg (rs1801278) polymorphism is associated with increased risk of PCOS in Kashmiri women. The correlation of various clinical, metabolic and hormonal markers with rs1801278 single nucleotide polymorphism was analyzed. The genotypic−phenotypic association of clinical manifestations of PCOS with the tested genetic variant was also assessed. Results: There were no significant differences in allele frequency (OR = 0.87, CI = 0.59−1.29, χ2 = 0.456, p = 0.499) or genotypic distribution (χ2 = 3.73, p = 0.15) between PCOS women and controls. No significant association was also found in the dominant (OR = 1.63, χ2 = 0.377, p = 0.53), recessive (OR = 0.79, χ2 = 1.01, p = 0.31) or heterozygote vs. homozygote (OR = 1.34, χ2 = 1.53, p = 0.22) genotype model analysis. The genotype−phenotype correlation analysis showed that the Arg allele was significantly associated with increased central adiposity markers hip circumference (p = 0.012), and body adiposity index BAI (p = 0.002) in the recessive model in PCOS women. The two-hour glucose (p = 0.04) and insulin resistance marker HOMA (p = 0.44) were significantly higher in Arg allele carriers. The androgen excess markers dehydroepiandrosterone sulfate DHEAS (p = 0.02), Ferriman−Gallwey score (p = 0.012), prevalence of acne, alopecia and hirsutism (all p < 0.01) were significantly elevated in the wild-type GG genotype. Conclusions:IRS-1Gly972Arg genetic variant does not increase the risk of PCOS in Kashmiri women. However, this polymorphism is associated with clinical manifestations of insulin resistance, obesity and hyperandrogenism, suggesting its possible role in variable phenotypic manifestations of PCOS.

Potential environmental toxicant exposure, metabolizing gene variants and risk of PCOS-A systematic review

Exposure of environmental toxicants such as potentially toxic metals and pesticides have largely been attributed to produce adverse effects on general women's health and to be more precise on the reproductive system. In order to explore exposure of toxicants and metabolizing gene variants as risk factor for polycystic ovarian syndrome (PCOS), literature search was carried out using the databases PubMed, Central Cochrane Library, Google Scholar, Science Direct with appropriate keywords upto 6 December 2020. While most of the studies indicate higher serum Cu concentration and lower concentration of Mn as risk factor, studies also report presence of higher pesticide concentration in PCOS women. Genes such as MTHFR, CYPs participate in the metabolism of toxicants and may show different response due to underlying genetic variants. Thus, toxicant exposure are to some extent responsible for the pathogenesis of syndrome through oxidative stress and endocrine disruption, but the susceptibility may vary due to the underlying genetic polymorphism of the exposed population.

Pathophysiological roles of chronic low-grade inflammation mediators in polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common hormonal imbalance disease in reproductive-aged women. Its basic characteristics are ovulatory dysfunction and ovarian overproduction of androgens that lead to severe symptoms such as insulin resistance, hirsutism, infertility, and acne. Notwithstanding the disease burden, its underlying mechanisms remain unknown, and no causal therapeutic exists. In recent years, further studies showed that inflammation processes are involved in ovulation and play a key role in ovarian follicular dynamics. Visceral adipose tissue can cause inflammatory response and maintenance of the inflammation state in adipocytes by augmented production of inflammatory cytokines, monocyte chemoattractant proteins, and recruitment of the immune cell. Therefore, the PCOS can be related to a low-grade inflammation state and inflammatory markers. Investigating the inflammatory processes and mediators that contribute to the commencement and development of PCOS can be a critical step for better understanding the pathophysiology of the disease and its treatment through inhibition or control of related pathways. In the present review, we discuss the pathophysiological roles of chronic low-grade inflammation mediators including inflammasome-related cytokines, interleukin-1β (IL-1β), and IL-18 in PCOS development.

Epidemiology, pathogenesis, genetics & management of polycystic ovary syndrome in India

Polycystic ovary syndrome (PCOS) is a common endocrine disorder predominantly affecting women of reproductive age. Clinical manifestations are diverse including hyperandrogenism, anovulation, infertility and increased risk of metabolic diseases besides psychosocial dysfunction. This review provides information on the problem of PCOS in India, its pathophysiology, genetics and an overview of current management options to instigate further research in this field. Prevalence of PCOS in India ranges from 3.7 to 22.5 per cent depending on the population studied and the criteria used for diagnosis. Abnormalities in leptin-adiponectin (adipocyte biology), oxidative stress and autoimmunity are among the mechanisms studied regarding pathogenesis of PCOS. Many candidate gene studies have shown associations with PCOS in various studies. Studies have consistently demonstrated the relationship between the well-known manifestation of hyperandrogenism among Indian PCOS women and the metabolic morbidities including insulin resistance, glucose intolerance and cardiovascular risk. Management of individual components of PCOS can be achieved by medications or surgical methods, though further clarification regarding pathogenesis of PCOS is needed to sharpen our therapeutic armamentarium.

Several critical genes and microRNAs associated with the development of polycystic ovary syndrome

BACKGROUND

We aimed to identify key genes and microRNAs (miRNAs) associated with the development of polycystic ovary syndrome (PCOS).

METHODS

GSE84376 mRNA microarray data (15 PCOS granulosa cells and 13 control granulosa cells) and GSE34526 mRNA microarray data (7 PCOS granulosa cells and 3 control granulosa cells) were downloaded from the Gene Expression Omnibus (GEO) database. First, differentially expressed gene (DEG) analysis, gene set enrichment analysis (GSEA) for differentially expressed mRNAs, and protein-protein interaction (PPI) network analysis were conducted. Next, miRNA-target genes were analyzed and functions predicted, and a competing endogenous RNA (ceRNA) network was constructed. Finally, the relationship between miR-486-5p and PRELID2 was experimentally validated.

RESULTS

Spleen tyrosine kinase (SYK), major histocompatibility complex, class II, DR alpha (HLA-DRA), and interleukin 10 (IL-10) were important nodes in the PPI network. Interestingly, HLA-DRA was significantly enriched in phagosomes mediated by Staphylococcus aureus infection, and in IL-10 enriched during S. aureus infection. One miRNA (miR-486-5p) and a single target gene (PRELID2) were obtained from the ceRNA network. Further experiments showed that miR-486-5p is upregulated and PRELID2 is downregulated in PCOS patient granulosa cells, and that miR-486-5p targets the PRELID2 3'UTR. Topological property analysis showed that hsa-miR-4687-5p downregulation and hsa-miR-4651 upregulation determined the levels of most mRNAs. Levels of the hsa-miR-4651 target gene were significantly enriched in the leukocyte transendothelial migration pathway.

CONCLUSIONS

Our results suggest that HLA-DRA and IL-10 may contribute to PCOS progression via phagosome enriched by S. aureus infection, while miR-486-5p may be implicated in follicular development in PCOS by targeting PRELID2. Besides, miR-4651 may be involved in inflammation via leukocyte transendothelial migration, by regulating its target gene. These findings may indicate new directions and constitute a breakthrough in studying the pathophysiology of PCOS.

Effect of testosterone on the expression of PPARγ mRNA in PCOS patients

Expression of peroxisome proliferator-activated receptor γ (PPARγ) mRNA in ovarian granulosa cells of patients with polycystic ovary syndrome (PCOS) were explored. Ovarian granulosa cells were extracted from 5 patients with PCOS and 30 normal controls. Expression of PPARγ mRNA in granulosa cells of the 5 PCOS patients (observation group) and 5 normal controls (control group) was detected by RT-qPCR. The remaining 25 cases of normal human ovarian granulosa cells were cultured in vitro for 48 h, followed by cell culture for another 24 h with different concentrations of testosterone, insulin (INS), and rosiglitazone (RGZ). After that, expression of PPARγ mRNA was detected by RT-qPCR. Relative expression level of PPARγ mRNA in the observation group was significantly lower than that in the control group. Compared with testosterone concentration at 10-2 mol/ml, testosterone concentration at 10-3 mol/ml significantly reduced the expression level of PPARγ mRNA. When the INS concentration was 10-5 mol/ml, relative expression level of PPARγ mRNA was significantly higher than that of the control group (P<0.01). Relative expression level of PPARγ mRNA was significantly higher than that of the control group when INS concentration was 10-4 mol/ml. When the concentration of RGZ was 10-4 mol/ml, the relative expression level of PPARγ mRNA was significantly higher than that of the control group (P<0.01). When concentration of RGZ was 10-3 mol/ml, expression level of PPARγ mRNA was significantly increased comparing to that under a RGZ concentration of 10-4 mol/ml or that of the control group (P<0.01). Appropriate concentrations of testosterone can inhibit the expression of PPARγ mRNA in ovarian granulosa cells, and certain concentrations of INS and RGZ can induce the expression of PPARγ mRNA in ovarian granulosa cells. Abnormal expression of PPARγ mRNA in ovarian granulosa cells may be related to the mechanism of PCOS.

Influence of peroxisome proliferator-activated receptor-γ exon 2 and exon 6 and insulin receptor substrate (IRS)-1 Gly972Arg polymorphisms on insulin resistance and beta-cell function in southern mediterranean women with polycystic ovary syndrome

Background and objective

The Pro12Ala (exon 2) and His447His (exon 6) polymorphisms of PPAR-γ, and Gly972Arg polymorphism of IRS-1 have been implicated in insulin resistance (IR) and adiposity. Our aim was to investigate the influence of these polymorphisms on metabolic features of polycystic ovary syndrome (PCOS).

Methods

Fifty-three PCOS women and 26 control women underwent a clinical and biochemical evaluation, including a 75-g oral glucose tolerance test. Insulin secretion and insulin sensitivity indices were calculated.

Results

Frequencies of PPAR-γ polymorphisms did not differ from those predicted by the Hardy-Weinberg equilibrium. Instead, the IRS-1 Gly972Arg allele was significantly more frequent in the PCOS group compared to controls. The most frequent allelic combinations were IRS1+/exon2-/exon6- (which prevailed in PCOS) and IRS-1-/exon2-/exon6- (which prevailed in controls). Among PCOS women, compared with the wild type patients, carriers of the Gly972Arg IRS-1 allele had lower E2 levels, while carriers of the Pro12Ala PPAR-γ (exon 2) allele had lower free testosterone levels. No other significant relationships were noted. When compared with the wild type, in PCOS group IR and beta-cell function were: (i) trendwise greater in carriers of the variant IRS-1 allele; (ii) trendwise lower in carriers of the variant PPAR-γ exon 6 allele; (iii) significantly lower in carriers of the variant PPAR-γ exon 2 allele.

Conclusions

Our data support the protective influence of PPAR-γ-exon 2 and exon 6 variants on IR and beta cell function, whereas IRS-1 polymorphism is associated with an unfavorable metabolic profile. However, these associations do not fully explain the high metabolic risk associated with PCOS.

Association of type 2 diabetes mellitus genes in polycystic ovary syndrome aetiology among women from southern India

BACKGROUND & OBJECTIVES

Polycystic ovary syndrome (PCOS) is the most common reproductive endocrine disorder of premenopausal women. Given the phenotypic overlap between PCOS and type 2 diabetes mellitus (T2DM), this study was carried out to investigate whether genes implicated in T2DM were also involved in the susceptibility to PCOS among women from southern India.

METHODS

A total of 248 women with PCOS and 210 healthy women as controls were genotyped for a panel of 15 single nucleotide polymorphisms (SNPs) from the nine T2DM genes, such as TCF7L2, IGF2BP2, SLC30A8, HHEX, CDKAL1, CDKN2A, IRS1, CAPN10 and PPARG, on Sequenom MassARRAY platform.

RESULTS

None of the 15 SNPs were found to be significantly associated with PCOS after Bonferroni correction for multiple testing, either in the univariate or multivariate context. The cumulative effect of risk alleles observed with reference to T2DM was also not seen with reference to PCOS.

INTERPRETATION & CONCLUSIONS

The nine T2DM genes considered in this exploratory study might not be the primary susceptibility factors for PCOS among Indian women. Our results supplement the lack of evidence of the association of T2DM genes with PCOS among the Chinese and Caucasians hinting at the possible universality of this pattern. Specifically designed comprehensive studies that include women with T2DM and PCOS are required to explore the precise role of the diabetes genes.

Single-nucleotide polymorphism of INS, INSR, IRS1, IRS2, PPAR-G and CAPN10 genes in the pathogenesis of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common and a complex female endocrine disorder, and is one of the leading cause of female infertility. Here, we aimed to investigate the association of single-nucleotide polymorphism of INS, INSR, IRS1, IRS2, PPAR-G and CAPN10 gene in the pathogenesis of PCOS. A hospital-based, observational case-control study was carried on 169 PCOS and 169 control women in the southern region of India. Genotype was carried out by real-time polymerase chain reaction. A chi-square (χ²) test was performed and the genotypes were verified to comply with the Hardy- Weinberg equilibrium. Odds ratio and 95% confidence interval were calculated to assess the relative risk. Comparison of clinical characteristics of women with PCOS and controls reveal an increase in body mass index (BMI), luteinizing hormone / follicle stimulating hormone (LH/FSH) ratio, glucose levels, insulin, testosterone, hirsutism and antral follicular count in PCOS women. The variant rs1801278 (P = 0.002; OR = 2.88; 95% CI = 1.43, 5.80) show an association with PCOS. In the genotypic (P = 0.0002) and allelic models (P = 0.000), significance persisted even after Bonferroni correction. The genotypes of SNPs strongly influence BMI, LH, LH/FSH ratio, ovarian volume and antral follicular count in PCOS women. The study results were suggestive of a positive association between Gly972Arg of IRS1 and PCOS in the south Indian population, while INS, IRS2, PPAR-G and CAPN10 failed to show any association with PCOS in our studied population. Further studies focussing the role of IRS1 are warranted to delineate its implication towards PCOS.

Distinct Patterns of Association of Variants at 11q23.3 Chromosomal Region with Coronary Artery Disease and Dyslipidemia in the Population of Andhra Pradesh, India

In our attempt to comprehensively understand the nature of association of variants at 11q23.3 apolipoprotein gene cluster region, we genotyped a prioritized set of 96 informative SNPs using Fluidigm customized SNP genotyping platform in a sample of 508 coronary artery disease (CAD) cases and 516 controls. We found 12 SNPs as significantly associated with CAD at P <0.05, albeit only four (rs2849165, rs17440396, rs6589566 and rs633389) of these remained significant after Benjamin Hochberg correction. Of the four, while rs6589566 confers risk to CAD, the other three SNPs reduce risk for the disease. Interaction of variants that belong to regulatory genes BUD13 and ZPR1 with APOA5-APOA4 intergenic variants is also observed to significantly increase the risk towards CAD. Further, ROC analysis of the risk scores of the 12 significant SNPs suggests that our study has substantial power to confer these genetic variants as predictors of risk for CAD, as illustrated by AUC (0.763; 95% CI: 0.729-0.798, p = <0.0001). On the other hand, the protective SNPs of CAD are associated with elevated Low Density Lipoprotein Cholesterol and Total Cholesterol levels, hence with dyslipidemia, in our sample of controls, which may suggest distinct effects of the variants at 11q23.3 chromosomal region towards CAD and dyslipidemia. It may be necessary to replicate these findings in the independent and ethnically heterogeneous Indian samples in order to establish this as an Indian pattern. However, only functional analysis of the significant variants identified in our study can provide more precise understanding of the mechanisms involved in the contrasting nature of their effects in manifesting dyslipidemia and CAD.

Association of PPARγ gene polymorphisms with osteoarthritis in a southeast Chinese population

Primary osteoarthritis (OA) is a leading cause of disability in developed countries. Currently no satisfactory treatment to stop disease progression exists. Recent studies suggest that activation of the transcription factor peroxisome proliferator-activated receptor gamma (PPARγ) is an interesting therapeutic target for this disease. PPARγ is a transcription factor important for adipogenesis and adipocyte differentiation. Agonists of PPARγ inhibit inflammation and reduce generation of cartilage degradation products both in vitro and in vivo, and reduce the development/progression of cartilage lesions in OA animal models. However, there are no studies to assess the role of PPARγ in OA susceptibility of human peripheral joints in a Chinese population. We conducted a case-control study in a southeast Chinese population to determine the association of PPARγ gene polymorphisms (rs1801282, rs12629751, rs2292101, rs4135275 and rs1175543) with OA. One-hundred knee OA cases and 100 controls were studied. Statistically significant differences were detected in genotype and allele frequencies between OA and control groups in this population. For knee OA, the highest risk was associated with the variant allele T of the single nucleotide polymorphism rs12629751 (odds ratio (OR): 0.341, 95% confidence interval (CI):0.173-0.673, P = 0.002), and allele T of SNP rs12629751 (chi-square: 9.546, P = 0.002) could be considered as a risk factor of knee OA. Therefore, PPARγ mutation could be associated with the incidence of OA in a Chinese population. There is a significant association between the PPARγ polymorphism rs12629751 and susceptibility to knee OA in a southeast Chinese population.

Phytoestrogens and the metabolic syndrome

Phytoestrogens are a diverse class of non-steroidal compounds that have an affinity for estrogen receptors α and β, for the peroxisome proliferator-activated receptor (PPAR) family and for the aryl hydrocarbon receptor. Examples of phytoestrogens include prenylated flavonoids, isoflavones, coumestans and lignans. Many phytoestrogens counteract the cellular derailments that are responsible for the development of metabolic syndrome. Here we propose a mechanism of action which is based on five pillars/principles. First, phytoestrogens are involved in the downregulation of pro-inflammatory cytokines, such as COX-2 and iNOS, by activating PPAR and by inhibiting IκB activation. Second, they increase reverse cholesterol transport, which is mediated by PPARγ. Third, phytoestrogens increase insulin sensitivity, which is mediated via PPARα. Fourth, they exert antioxidant effects by activating antioxidant genes through KEAP. Fifth, phytoestrogens increase energy expenditure by affecting AMP-activated kinase signaling cascades, which are responsible for the inhibition of adipogenesis. In addition to these effects, which have been demonstrated in vivo and in clinical trials, other effects, such as eNOS activation, may also be important. Some plant extracts from soy, red clover or licorice can be described as panPPAR activators. Fetal programming for metabolic syndrome has been hypothesized; thus, the consumption of dietary phytoestrogens during pregnancy may be relevant. Extracts from soy, red clover or licorice oil have potential as plant-derived medicines that could be used to treat polycystic ovary syndrome, a disease linked to hyperandrogenism and obesity, although clinical trials have not yet been conducted. Phytoestrogens may help prevent metabolic syndrome, although intervention studies will be always be ambiguous, because physical activity and reduced calorie consumption also have a significant impact. Nevertheless, extracts rich in phytoestrogens may be an alternative treatment or may complement conventional treatment for diseases linked with metabolic syndrome. This article is part of a Special Issue entitled 'Phytoestrogens'.

Genetic variants associated with insulin signaling and glucose homeostasis in the pathogenesis of insulin resistance in polycystic ovary syndrome: a systematic review

BACKGROUND

Polycystic ovary syndrome must be recognized as a serious issue due to its implication on long term health regardless of an individual's age. PCOS and insulin resistance are interlinked, as approximately 40 % of women with PCOS are insulin resistant. However, the detailed molecular basis for insulin resistance that is coupled with PCOS remains poorly understood.

OBJECTIVE

To review the published evidence that polymorphisms in genes that are involved in insulin secretion and action are associated with an increased risk of PCOS.

METHODS

We reviewed articles published through November 2012 which concerned polymorphisms of genes related to insulin signaling and glucose homeostasis as well as their associations with PCOS. The articles were identified via Medline searches.

CONCLUSIONS

No consistent evidence emerged of a strong association between the risk of PCOS and any known gene that is related to insulin signaling and glucose homeostasis. Moreover, recent genome-wide association studies are inconsistent in identifying the associations between PCOS and insulin metabolism genes. Many of the studies reviewed were limited by heterogeneity in the PCOS diagnosis and by not have having a sufficient number of study participants. Further studies are warranted to determine predisposing risk factors which could modify environmental factors and thus reduce the risk of PCOS. Large genome-wide association studies devoted solely to PCOS will be necessary to identify new candidate genes and proteins that are involved in PCOS risk.

Peroxisome proliferator activated receptor gamma gene variants influence susceptibility and insulin related traits in Indian women with polycystic ovary syndrome

PURPOSE

Peroxisome proliferator activated receptor gamma (PPARγ), a transcription factor involved in glucose and lipid metabolism is one of the candidate genes associated with polycystic ovary syndrome (PCOS). We investigated individual and combined associations of Pro12Ala and His447His polymorphisms of PPARγ with PCOS susceptibility and its related traits (hyperinsulinemia, hyperandrogenemia and lipid parameters) in Indian women.

METHOD

Genotyping of PPARγ polymorphisms in this case-control study was performed in PCOS (n = 450) and age-matched controls (n = 300) by direct sequencing. Clinical, anthropometric, hormonal and metabolic parameters were estimated in 275 women with PCOS and 169 controls. Chi-square test was used to compare the categorical data while regression analysis was used to evaluate association of genotypes with PCOS as well as its related phenotypes.

RESULTS

The frequencies of CC and CG + GG genotypes of Pro12Ala (χ² = 15.3, p < 0.0001) and CC and CT + TT genotypes of His447His (χ² = 12.7, p = 0.0004) polymorphisms were significantly different between PCOS and controls. Logistic regression analysis revealed a significant association of PCOS with Pro12Ala but not the His447His polymorphism. Carriers of variant genotypes at both PPARγ loci showed significantly reduced 2 h glucose levels while carriers of variant His447His genotype showed lower fasting insulin and HOMA-IR levels in PCOS women.

CONCLUSIONS

Pro12Ala polymorphism of PPARγ showed significant association with decreased PCOS susceptibility. Both polymorphisms influenced insulin related traits (2 h glucose, fasting insulin and HOMA-IR) and improved glucose metabolism in these women. This is the first report to establish that variations in PPARγ gene influence the insulin resistance pathophysiology in Indian women with PCOS.

Predictors of insulin resistance and metabolic complications in polycystic ovarian syndrome in an eastern Indian population

The purpose of this study was to assess the predictive values of central obesity and hyperandrogenemia in development of insulin resistance and dyslipidemia in the polycystic ovarian syndrome (PCOS) patients in our region. Differences of fasting blood glucose level, insulin resistance index HOMA-IR, lipid parameters, waist hip ratio (WHR), body mass index, LH/FSH ratio and testosterone levels between 45 PCOS cases and 35 age matched controls were obtained. Strength of association between different parameters in the case group was assayed by Pearson's correlation analysis. Dependence of insulin resistance and WHR on different predictors was assessed by multiple linear regression assay. Total cholesterol, LDL cholesterol, LH, FSH, LH/FSH ratio, WHR and insulin resistance were significantly higher in the case group (p < 0.05). Serum testosterone showed strong correlation with insulin resistance and LH/FSH ratio (r = 0.432 and 0.747, p = 0.01 and 0.001 respectively) in the PCOS patients while WHR and serum testosterone level stood out to be most significant predictors for the insulin resistance (β = 0.361 and 0.498; p = 0.048 and 0.049 respectively). Hyperandrogenemia and central obesity were the major factors predicting development of insulin resistance and its related metabolic and cardiovascular complications in our PCOS patients. We suggest early monitoring for androgen level and WHR in these patients for predicting an ensuing insulin resistance and modulating the treatment procedure accordingly to minimise future cardiovascular risks.