Metabolically healthy obesity "worst"-increases risk of prehypertension and hypertension

CHINA: The results of recent research published in the Diabetology and Metabolic syndrome, BMC has linked Metabolically Healthy Obesity (MHO) with increased risk of prehypertension and hypertension, more in young adults. The researchers highlighted the importance of obesity intervention strategies, adding, even though abdominal adiposity may be related to a healthy metabolic state, it increases cardiometabolic risk more in men than women.

Metabolically healthy general obesity (MHGO) is defined as obesity not associated with cardiometabolic abnormality (CA). Obesity is related to high dietary fat and lack of physical activity. This leads to overburdened cardiovascular diseases (CVD) and is a major cause of public health concern.

The relationship between MGHO and CVD remains controversial. Some studies mention that MGHO did not significantly increase arterial stiffness, compared with the metabolically healthy normal weight. In contrast, other studies have tied MGHO with higher coronary heart disease and heart failure risks.

The link between MHO and hypertension remains unestablished. The prevalence of obesity is 51.2%, and hypertension is 27.5% in China, estimated to reach 70.5% and 35.4% in 2030. In rural areas of China, abnormal adiposity is positively tied to an increased risk of hypertension, according to a recent study. Abnormal lipid and glucose metabolism increases the pro-inflammatory proteins and inflammatory cytokines, which drives hypertension development due to oxidative stress.

Based on the above background, a study was conducted by Dr. Yue Yuan from the Department of Cardiology at The First Affiliated Hospital of Nanjing Medical University along with co-researcher Dr. Wei Sun and Dr. Kong to explore the effect of combined metabolic state (general and abdominal adiposity) and obesity on the prevalence of prehypertension and hypertension.

In the present study, abdominal obesity was classified as waist circumference (WC) ≥ 90 cm in men and ≥ 80 cm in women, while general obesity was classified as BMI ≥ 25.0 kg/m2.

The study highlights how individual treatment strategies are impacted by obesity, and the study's results can aid in developing risk-stratified obesity treatments.

The key highlights of the study are:

• 4764 participants were enrolled from the China Health and Nutrition Survey.

• The follow-up period was from 2009 to 2015.

• Fasting blood samples were collected in 2009.

• The relationship between MHO and prehypertension was analyzed using logistic regression.

• 37.9% of participants had prehypertension.

• 41.0% of participants had hypertension and metabolically healthy abdominal obesity (MHAO).

• The odds ratio for prehypertension was 1.89 with a p-value  < 0.001, and for hypertension was 2.58 with a p-value < 0.001. These values indicate that participants with the MHAO phenotype had significantly higher prehypertension and hypertension risks than metabolically healthy individuals without abdominal obesity.

• Men with the MHAO phenotype had higher prehypertension risks than women with OR 2.42 and 1.76 (men vs. women).

• Similarly, the men were at higher risk of hypertension than women, with an OR of 3.80 vs. 2.22 compared to metabolically healthy participants without abdominal obesity.

The lead researcher wrote, "Our findings show those with general obesity and abdominal obesity are at high risk of hypertension despite of metabolic state." They added, "We analyzed that men with MHAO have higher ORs of hypertension than women."

Adipose tissue accumulates around the abdomen in men and around the hips and thighs in women, so it can be concluded that obesity may lead to adverse events, and reducing abdominal fat may reduce the adverse outcomes associated with obesity. When the abdominal fat reduces, insulin sensitivity increases, the cardiovascular risk gets reduced, and an improved prognosis can be achieved.

Cardiometabolic risk is more in men than women pertaining to abdominal adiposity with a healthy metabolic state. These findings of our study are in line with the previous studies.

The final conclusion by the researchers is, "We suggest that obesity should be intervened early to prevent subsequent adverse events associated with hypertension."

This study had limitations like racial homogeneity, the absence of data on fat distribution, the lack of adjustment for biochemical data, etc.

The work was supported by the 70th batch of the China Postdoctoral Science Foundation, the Postdoctoral Research Program of Jiangsu Province, and the Doctoral Program of Entrepreneurship and Innovation in Jiangsu Province. The researchers thanked National Institute for Health (NIH) Fogarty program and the Eunice Kennedy Shriver National Institute of Child Health and Human Development for the financial support.

Reference:

Yuan, Y., Sun, W. & Kong, X. Relationship between metabolically healthy obesity and the development of hypertension: a nationwide population-based study. Diabetol Metab Syndr 14, 150 (2022). https://doi.org/10.1186/s13098-022-00917-7