Risk of hypertension among different metabolic phenotypes: a systematic review and meta-analysis of prospective cohort studies

Metabolically healthy obesity: from epidemiology and mechanisms to clinical implications

The concept of metabolic health, particularly in obesity, has attracted a lot of attention in the scientific community, and is being increasingly used to determine the risk of cardiovascular diseases and diabetes mellitus-related complications. This Review assesses the current understanding of metabolically healthy obesity (MHO). First, we present the historical evolution of the concept. Second, we discuss the evidence for and against its existence, the usage of different definitions of MHO over the years and the efforts made to provide novel definitions of MHO. Third, we highlight epidemiological data with regard to cardiovascular risk in MHO, which is estimated to be moderately elevated using widely used definitions of MHO when compared with individuals with metabolically healthy normal weight, but potentially not elevated using a novel definition of MHO. Fourth, we discuss novel findings about the physiological mechanisms involved in MHO and how such knowledge helps to identify and characterize both people with MHO and those with metabolically unhealthy normal weight. Finally, we address how the concept of MHO can be used for risk stratification and treatment in clinical practice.

Macronutrient quality and the incidence of metabolically unhealthy phenotypes in adults with normal weight and overweight/obesity

OBJECTIVE

We aimed to investigate the associations of macronutrient quality indices with the incident metabolically unhealthy normal weight (MUNW) and metabolically unhealthy overweight/obesity (MUO) phenotypes.

METHODS

This prospective study included 512 metabolically healthy normal weight and 787 metabolically healthy overweight/obese adults from the third study examination of the Tehran Lipid and Glucose Study. The participants were followed through the sixth study examination. Diet was measured with a food frequency questionnaire. The macronutrient quality index (MQI), carbohydrate quality index (CQI), fat quality index (FQI), and healthy plate quality index (HPPQI) were calculated. Hazard ratio (HR) and 95 % confidence interval (95 % CI) were estimated for incident unhealthy phenotypes using Cox regression.

RESULTS

After controlling all possible confounding factors, a one-point higher HPPQI was linked to a 28 % lower risk of MUNW (HR = 0.72; 95 % CI = 0.59, 0.87). Compared to the lowest quartile, the incident MUNW was also lower in the two last quartiles of the HPPQI. A one-unit increase in MQI was associated with a 5 % lower incident MUO (HR = 0.95; 95 % CI = 0.92, 0.99). The incident MUO was also higher for the highest compared to the lowest MQI quartile. In quartiles 2-4 of the HPPQI, incident MUO was lower with respective HRs (95 % CI) of 0.71 (0.54, 0.93), 0.60 (0.45, 0.80), and 0.66 (0.50, 0.86) in the fully-adjusted model.

CONCLUSIONS

A higher overall macronutrient quality was independently associated with a lower incident MUO. A higher dietary protein quality was related to a lower risk for MUNW and MUO.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Sex-specific differences in the association between metabolically healthy overweight/obesity and the risk of hypertension in Chinese ethnic minorities

OBJECTIVE

To estimate and compare sex-specific differences between metabolically healthy overweight/obesity (MHOO) and the risk of hypertension among Dong, Bouyei, and Miao adults in southwest China.

METHODS

MHOO was diagnosed when the patient had a body mass index ≥24 kg/m² and the presence of ≤1 component of metabolic syndrome. The main outcome was the occurrence of hypertension after the diagnosis or measurement by a physician at the baseline survey. Multivariate logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) between MHOO and the risk of hypertension.

RESULTS

We enrolled 16,433 Chinese Dong, Bouyei, and Miao adults. Using the metabolically healthy normal weight (MHNW) as a reference and after adjusting for confounders, the association between MHOO and the risk of hypertension was stronger in Dong (OR = 1.46, 95% CI: 1.07-2.00) and Miao (OR = 2.05, 95% CI: 1.48-2.85) men and did not exist in Bouyei men (OR = 1.14, 95% CI: 0.81-1.60). After adjusting for the age, the association between MHOO and the risk of hypertension was stronger in men than in women among Dong adults aged 30-59 years (OR = 1.64, 95% CI: 1.12-2.40) and did not differ between men and women among Dong adults aged 60-79 years or among Miao or Bouyei adults.

CONCLUSION

The results of this study demonstrated sex-specific differences in the association between MHOO and the risk of hypertension and that sex-specific differences further differed among Dong, Bouyei, and Miao adults.

Association between Metabolic Phenotypes of Body Fatness and Incident Stroke: A Prospective Cohort Study of Chinese Community Residents

This study aimed to assess the association of body mass index (BMI)-based and waist circumference (WC)-based metabolic phenotypes with the risk of stroke among Chinese community residents. A total of 34,294 participants (mean ± standard deviation age: 56.05 ± 11.26 years) with no previous stroke diagnosis history were included in this cohort study. BMI-based metabolic phenotypes were classified into eight groups: metabolically healthy and normal weight (MHNW), metabolically healthy and underweight (MHUW), metabolically healthy and overweight (MHOW), metabolically healthy and obese (MHO), metabolically unhealthy and normal weight (MUNW), metabolically unhealthy and underweight (MUUW), metabolically unhealthy and overweight (MUOW), and metabolically unhealthy and obese (MUO). WC-based metabolic phenotypes were classified into four groups: metabolically healthy and normal WC (MHNWC), metabolically healthy and oversized WC (MHOWC), metabolically unhealthy and normal WC (MUNWC), and metabolically unhealthy and oversized WC (MUOWC). The association of these phenotypes with developing stroke events was examined using proportional hazards models. A total of 546 cases of first-stroke onset were recorded over a median follow-up time of 4.97 years. Compared with the reference group, the obesity phenotypes showed higher risks for stroke. The adjusted HRs (95% CIs) of MHUW, MHOW, MHO, MUNW, MUUW, MUOW, and MUO phenotypes were 1.01 (0.41, 2.49), 1.47 (1.09, 2.00), 1.33 (0.80, 2.22), 2.49 (1.87, 3.30), 3.92 (1.44, 10.72), 2.14 (1.64, 2.79), and 2.60 (1.91, 3.55), respectively. The adjusted HRs (95% CIs) of MHOWC, MUNWC, and MUOWC were 1.41 (1.02, 1.94), 2.25 (1.76, 2.87), and 2.16 (1.63, 2.87), respectively. The metabolic phenotypes defined by an alternative definition all showed significant positive associations (except for MHUW), with the adjusted HR ranging from 1.51 to 3.08 based on BMI and from 1.68 to 2.24 based on WC. The risk of stroke increased with the increase in metabolic abnormality numbers in different BMI and WC groups (all p trend < 0.001). The present study suggests that maintaining normal body weight or WC and improving metabolic health are of great significance in preventing cerebrovascular diseases.

Relationship between metabolically healthy obesity and the development of hypertension: a nationwide population-based study

BACKGROUND

Metabolically healthy obesity (MHO), has been recognized as a transient phenotype with few cardiometabolic diseases; however, little is known regarding the development of hypertension in subjects with an absence of cardiometabolic abnormalities and general obesity evaluated by body mass index (BMI) or abdominal obesity evaluated by waist circumference (WC).

METHODS

A total of 4764 participants were enrolled from the China Health and Nutrition Survey and followed up from 2009 to 2015, whose fasting blood samples were collected in 2009. Obesity was classified as abdominal obesity (WC ≥ 90 cm in men and ≥ 80 cm in women) and general obesity (BMI ≥ 25.0 kg/m²). Logistic regression was used to analyze the relationship between MHO and prehypertension (120 < SBP < 140 mmHg or 80 < DBP < 90 mmHg) and hypertension (SBP ≥ 140 or DBP ≥ 90 mmHg). The age- and sex-specific impacts were further analyzed.

RESULTS

There were 412 (37.9%) participants with prehypertension and 446 (41.0%) participants with hypertension and metabolically healthy abdominal obesity (MHAO). The participants with the MHAO phenotype had significantly higher risks of prehypertension [odds ratio (OR) = 1.89 (1.51-2.36), p < 0.001] and hypertension [OR = 2.58 (2.02-3.30), p < 0.001] than those metabolically healthy but without abdominal obesity. Similar associations were observed in the subjects with metabolically healthy general obesity (MHGO) phenotype, particularly those aged under 64 years. Men with the MHAO phenotype seemed to have higher risks of prehypertension [2.42 (1.52-3.86) in men vs. 1.76 (1.36-2.29) in women] and hypertension [3.80 (2.38-6.06) in men vs. 2.22 (1.64-3.00) in women] than women, when compared with those metabolically healthy but without abdominal obesity.

CONCLUSION

The MHO phenotype, regardless of the presence of general or abdominal obesity, showed a worse effect on the development of prehypertension and hypertension, particularly in young adults. Abdominal adiposity with a healthy metabolic state is significantly associated with incident hypertension in both men and women. These findings can guide the establishment of risk-stratified obesity treatments.

Risk of Stroke Among Different Metabolic Obesity Phenotypes: A Systematic Review and Meta-Analysis

Background and Purpose

Overweight/obesity is a modified risk factor for stroke. This systematic review and meta-analysis aimed to assess the impact of different obesity phenotypes on stroke risk in adults.

Methods

The PubMed, Embase, and Cochrane Library databases were searched from their inception to 7 March 2021 to identify the prospective cohort studies investigating stroke risk among different metabolic overweight/obesity phenotypes. The methodological quality of the included studies was evaluated using the Newcastle–Ottawa Scale. Pooled hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated using a random-effects model.

Results

A total of eleven prospective cohorts (n = 5,609,945 participants) were included in the systematic review, nine of which were included in the meta-analysis. All metabolically unhealthy phenotypes had a higher risk of stroke than the metabolically healthy normal-weight phenotypes, including metabolically unhealthy normal weight (HR = 1.63, 95% CI: 1.41–1.89, I² = 89.74%, n = 7 cohort studies, 1,042,542 participants), metabolically unhealthy overweight (HR = 1.94, 95% CI: 1.58–2.40, I² = 91.17%, n = 4 cohort studies, 676,166 participants), and metabolically unhealthy obese (HR = 1.99, 95% CI: 1.66–2.40, I² = 93.49%, n = 6 cohort studies, 1,035,420 participants) phenotypes. However, no risk of stroke was observed in the populations with metabolically healthy overweight (MHOW) (HR = 1.07, 95% CI: 1.00–1.14, I² = 69.50%, n = 5 studies, 4,171,943 participants) and metabolically healthy obese (MHO) (HR = 1.07, 95% CI: 0.99–1.16, I² = 54.82%, n = 8 studies, 5,333,485 participants) phenotypes. The subgroup analyses for the MHO studies suggested that the risk of stroke increased only when the MHO participants were mainly females, from North America, and when the World Health Organization standard was applied to define obesity. In the subgroup analysis of the risk of stroke in MHOW, a longer follow-up duration was also associated with a higher risk of stroke.

Conclusion

The risk of stroke increase for all metabolically unhealthy phenotypes irrespective of the body mass index (BMI). The associated risk of stroke with metabolic health but high BMI shows substantial heterogeneity, which requires future research considering the impact of sex and transition of the metabolic status on the risk of stroke.

Systematic Review Registration

The study protocol was prospectively registered in PROSPERO (No. CRD42021251021).

Metabolic phenotypes and risk of colorectal cancer: a systematic review and meta-analysis of cohort studies

BACKGROUND

The association of obesity with colorectal cancer (CRC) may vary depending on metabolic status.

OBJECTIVE

This meta-analysis aimed to investigate the combined impacts of obesity and metabolic status on CRC risk.

METHODS

The Scopus, PubMed, and web of sciences databases were systematically searched up to Jun 2021 to find all eligible publications examining CRC risk in individuals with metabolically unhealthy normal-weight (MUHNW), metabolically healthy obesity (MHO), and metabolically unhealthy obesity (MUHO) phenotypes.

RESULTS

A total of 7 cohort studies with a total of 759,066 participants were included in this meta-analysis. Compared with healthy normal-weight people, MUHNW, MHO, and MUHO individuals indicated an increased risk for CRC with a pooled odds ratio of 1.19 (95% CI = 1.09-1.31) in MUHNW, 1.14 (95% CI = 1.06-1.22) in MHO, and 1.24 (95% CI = 1.19-1.29) in MUHO subjects. When analyses were stratified based on gender, associations remained significant for males. However, the elevated risk of CRC associated with MHO and MUHO was not significant in female participants.

CONCLUSIONS

The individuals with metabolic abnormality, although at a normal weight, have an increased risk for CRC. Moreover, obesity is associated with CRC irrespective of metabolic status.

Visceral adiposity index performed better than traditional adiposity indicators in predicting unhealthy metabolic phenotype among Chinese children and adolescents

The relationship between visceral adiposity index (VAI) and unhealthy metabolic phenotype remained unclear in children and adolescents. This study aimed to investigate their association and compared the ability of VAI and traditional adiposity indicators (body mass index, waist circumference and waist-to-height ratio) to predict metabolically unhealthy phenotype among normal-weight, overweight and obese children and adolescents. In this cross-sectional study, 1722 children and adolescents aged 12-18 years were selected by cluster random sampling, underwent a questionnaire survey, physical examination and biochemical tests. Participants were divided into four phenotypes according to the combination of the weight status determined by body mass index (BMI) and metabolic syndrome components. Receiver operating characteristic (ROC) analysis and multivariate logistic regression were used to compare the predictive capacity between VAI and traditional adiposity indicators and their relationship with metabolically unhealthy phenotype. We found that VAI had better performance in predicting metabolically unhealthy phenotype than traditional adiposity indicators, the area under the receiver-operating characteristic curve (AUC) were 0.808 and 0.763 for boys and girls with normal-weight, 0.829 and 0.816 for boys and girls with overweight and obese (all P < 0.001). VAI was most strongly related to metabolically unhealthy phenotype whether or not to adjust the age, the adjusted OR and 95%CI was 6.15 (4.13-9.14) in boys with normal weight, and 5.90 (3.06-11.36), 4.95 (2.35-10.41) in boys and girls with overweight and obese, respectively (all P < 0.001). Our findings suggested VAI could be used as a comprehensive predictor to identify unhealthy metabolic phenotype in children and adolescents.

Children's Lipid Accumulation Product Combining Visceral Adiposity Index is a Novel Indicator for Predicting Unhealthy Metabolic Phenotype Among Chinese Children and Adolescents

PURPOSE

The predictive capacity between children's lipid accumulation product (CLAP) combining visceral adiposity index (VAI), CLAP, and VAI with metabolically unhealthy phenotype remained unclear. This study aimed to compare the ability of CLAP combining VAI, CLAP, VAI and traditional adiposity indicators (body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHtR) and waist-to-hip ratio (WHR)) to predict metabolically unhealthy phenotype among Chinese children and adolescents.

PATIENTS AND METHODS

In the cross-sectional study, 1714 children and adolescents aged 12 to 18 were selected by random cluster sampling, underwent a questionnaire survey, physical examination, biochemical tests and body composition was measured by bioelectrical impedance analysis (BIA). Participants were divided into four phenotypes according to BMI and metabolic syndrome components. The logarithmic CLAP (LnCLAP), VAI, BMI, WC, WHtR and WHR were standardized for sex and age using the z-score method (standardized variables: LnCLAP-z, VAI-z, BMI-z, WC-z, WHtR-z and WHR-z).

RESULTS

LnCLAP-z ≥ 1, VAI-z ≥ 1, WC-z ≥ 1, and WHR-z ≥ 1 increased the risk of metabolically unhealthy normal-weight phenotype (the OR and 95% CI were 4.18 (1.75-10.02), 24.05 (12.79-45.21), 6.17 (1.14-33.51), 2.69 (1.07-6.72), respectively), LnCLAP-z ≥ 1, VAI-z ≥ 1 and WC-z ≥ 1 increased the risk of metabolically unhealthy overweight or obese phenotype (the OR and 95% CI were 2.67 (1.40-5.09), 10.30 (3.03-35.03), 2.19 (1.18-4.09), respectively). The area under the ROC curve (AUC) for CLAP combining VAI in the prediction of the metabolically unhealthy phenotype were 0.837 (0.776-0.899) and 0.876 (0.834-0.918) for boys and girls with normal-weight, 0.853 (0.803-0.903) and 0.794 (0.711-0.878) for boys and girls with overweight and obese (all P < 0.001), which were higher than CLAP, VAI, BMI, WC, WHtR and WHR.

CONCLUSION

Among Chinese children and adolescents, CLAP combining VAI was a more effective indicator than CLAP, VAI and traditional adiposity indicators in predicting unhealthy metabolic phenotype.

Lifestyle interventions for the prevention and treatment of hypertension

Hypertension affects approximately one third of the world's adult population and is a major cause of premature death despite considerable advances in pharmacological treatments. Growing evidence supports the use of lifestyle interventions for the prevention and adjuvant treatment of hypertension. In this Review, we provide a summary of the epidemiological research supporting the preventive and antihypertensive effects of major lifestyle interventions (regular physical exercise, body weight management and healthy dietary patterns), as well as other less traditional recommendations such as stress management and the promotion of adequate sleep patterns coupled with circadian entrainment. We also discuss the physiological mechanisms underlying the beneficial effects of these lifestyle interventions on hypertension, which include not only the prevention of traditional risk factors (such as obesity and insulin resistance) and improvements in vascular health through an improved redox and inflammatory status, but also reduced sympathetic overactivation and non-traditional mechanisms such as increased secretion of myokines.

Metabolically healthy general and abdominal obesity are associated with increased risk of hypertension

Metabolically healthy obesity refers to a subset of obese people with a normal metabolic profile. We aimed to explore the association between metabolically healthy and obesity status and risk of hypertension among Chinese adults from The Rural Chinese Cohort Study. This prospective cohort study enrolled 9137 Chinese adults without hypertension, type 2 diabetes or treatment for lipid abnormality at baseline (2007–2008) and followed up during 2013–2014. Modified Poisson regression models were used to examine the risk of hypertension by different metabolically healthy and obesity status, estimating relative risks (RR) and 95 % CI. During 6 years of follow-up, we identified 1734 new hypertension cases (721 men). After adjusting for age, sex, smoking and other confounding factors, risk of hypertension was increased with metabolically healthy general obesity (MHGO) defined by BMI (RR 1·75, 95 % CI 1·02, 3·00) and metabolically healthy abdominal obesity (MHAO) defined by waist circumference (RR 1·51, 95 % CI 1·12, 2·04) as compared with metabolically healthy non-obesity. The associations between metabolically healthy and obesity status and hypertension outcome were consistent after stratifying by sex, age, smoking, alcohol drinking and physical activity. Both MHGO and MHAO were associated with increased risk of hypertension. Obesity control programmes should be implemented to prevent or delay the development of hypertension in rural China.

Interaction between mitochondrial NADH dehydrogenase subunit-2 5178 C > A and clinical risk factors on the susceptibility of essential hypertension in Chinese population

BACKGROUND

The mitochondrial genotype 5178 cytosine/adenine (5178 C > A) within the NADH dehydrogenase subunit-2 gene (ND2) was proved to associate with longevity and predispose resistance to adult-onset diseases. This study aimed to confirm the interactive effects between ND 25178 C > A and clinical risk factors on the susceptibility of essential hypertension in Chinese general population.

MATERIALS AND METHODS

The relationship between the ND2 5178 C > A variation and the risk of hypertension was investigated in 817 hypertensives and 821 matched normotensives. The interactive effects between ND2 5178 C > A and clinical risk factors were evaluated.

RESULTS

The ND2 5178 A allele was more frequent in normotensives than in hypertensives (32.64% vs. 24.24%; adjusted OR: 0.62, 95% CI: 0.49-0.79, P = 1.3 × 10^- 4). After stratification, the significant association between ND2 5178 C > A and hypertension was found only in current smokers (OR: 0.44, 95% CI: 0.31-0.62), but not in non-current smokers (p <  0.01 for interaction). Smoking status (OR: 1.51, 95% CI: 1.11-2.06) and high triglycerides (OR: 1.57, 95% CI: 1.10-2.24) were found independently associated with hypertension only in carriers of 5178 C allele but not in carriers of 5178 A allele.

CONCLUSIONS

In conclusion, ND2 5178 A allele could confer a lower risk for essential hypertension in Chinese by the interaction with smoking status. The higher risk of hypertension imposed by smoking and high TG may be altered by ND2 5178 A allele.