Association of Serum Aldosterone and Plasma Renin Activity With Ambulatory Blood Pressure in African Americans: The Jackson Heart Study.

BACKGROUND: The renin-angiotensin-aldosterone system (RAAS) is an important driver of blood pressure (BP), but the association of the RAAS with ambulatory BP (ABP) and ABP monitoring phenotypes among African Americans has not been assessed. METHODS: ABP and ABP monitoring phenotypes were assessed in 912 Jackson Heart Study participants with aldosterone and plasma renin activity (PRA). Multivariable linear and logistic regression analyses were used to analyze the association of aldosterone and PRA with clinic, awake, and asleep systolic BP and diastolic BP (DBP) and ABP monitoring phenotypes, adjusting for important confounders. RESULTS: The mean age of participants was 59±11 years and 69% were female. In fully adjusted models, lower log-PRA was associated with higher clinic, awake, and asleep systolic BP and DBP (all P<0.05). A higher log-aldosterone was associated with higher clinic, awake, and asleep DBP (all P<0.05). A 1-unit higher log-PRA was associated with lower odds of daytime hypertension (odds ratio [OR] 0.59 [95% CI, 0.49-0.71]), nocturnal hypertension (OR, 0.68 [95% CI, 0.58-0.79]), daytime and nocturnal hypertension (OR, 0.59 [95% CI, 0.48-0.71]), sustained hypertension (OR, 0.52 [95% CI, 0.39-0.70]), and masked hypertension (OR 0.75 [95% CI, 0.62-0.90]). A 1-unit higher log-aldosterone was associated with higher odds of nocturnal hypertension (OR, 1.38 [95% CI, 1.05-1.81]). Neither PRA nor aldosterone was associated with percent dipping, nondipping BP pattern, or white-coat hypertension. Patterns for aldosterone:renin ratio were similar to patterns for PRA. CONCLUSIONS: Suppressed renin activity and higher aldosterone:renin ratios were associated with higher systolic BP and DBP in the office and during the awake and asleep periods as evidenced by ABP monitoring. Higher aldosterone levels were associated with higher DBP, but not systolic BP, in the clinic and during the awake and asleep periods. Further clinical investigation of novel and approved medications that target low renin physiology such as epithelial sodium channel inhibitors and mineralocorticoid receptor antagonists may be paramount in improving hypertension control in African Americans.

The role of aldosterone and ideal cardiovascular health in incident diabetes: The Jackson Heart Study.

Background: Greater attainment of ideal cardiovascular health (ICH) and lower serum aldosterone are associated with lower diabetes risk. Higher levels of ICH are associated with lower aldosterone. The mediational role of aldosterone in the association of ICH with incident diabetes remains unexplored. Thus, we examined the mediational role of aldosterone in the association of 5 ICH components (smoking, diet, physical activity, body mass index [BMI], and cholesterol) with incident diabetes. Additionally, we investigated the mediational role of glucose and blood pressure (BP) in the association of aldosterone with incident diabetes in an African American (AA) cohort. Methods: We conducted a prospective cohort analysis among AA adults, aged 21-94 years, in the Jackson Heart Study. Data on ICH, aldosterone, and cardiometabolic risk factors were collected at exam 1 (2000-2004). Diabetes (fasting glucose ≥ 126 mg/dL, physician diagnosis, use of diabetes drugs, or glycated hemoglobin ≥ 6.5%) was assessed at exams 1 through 3 (2009-2012). ICH metrics were defined by American Heart Association 2020 goals for smoking, dietary intake, physical activity, BMI, total cholesterol, BP and glucose. The number of ICH metrics attained at exam 1, excluding BP and fasting glucose, were summed (0-2, vs. 3+). R Package Mediation was used to examine: 1) The mediational role of aldosterone in the association of ICH with incident diabetes; and 2) the mediational role of BP and glucose in the association of aldosterone with incident diabetes. Results: Among 2,791 participants (mean age: 53±12, 65% female) over a median of 7.5 years, there were 497 incident diabetes cases. Risk of incident diabetes was 37% (HR: 0.63, 95%CI: 0.47, 0.84) lower in 3+ ICH category compared to 0-2 ICH category. Aldosterone mediated 6.98% (95% CI: 1.8%, 18.0%) of the direct effect of ICH on incident diabetes. A 1-unit increase in log-aldosterone was associated with a 44% higher risk of diabetes (HR 1.44, 95%CI 1.25-1.64). BP and glucose mediated 16.3% (95% CI: 7.0%, 31.0%) and 19.7% (95% CI: 6.5%, 34.0%) of the association of aldosterone with incident diabetes, respectively. Conclusion: Aldosterone is a mediator of the association of ICH with incident diabetes, whereas BP and glucose are mediators of the association of aldosterone with incident diabetes, emphasizing the importance of the renin-angiotensin-aldosterone system and ICH in lowering risk of diabetes in AA populations.

Adiposity, aldosterone and plasma renin activity among African Americans: The Jackson Heart Study.

Objective: To analyze associations between adiposity and the renin-angiotensin-aldosterone system (RAAS) in a large African American (AA) cohort. Methods: Cross-sectional associations of adiposity (body mass index [BMI], waist circumference [WC], waist:height ratio, waist:hip ratio, leptin, adiponectin, leptin:adiponectin ratio [LAR], subcutaneous [SAT] and visceral adipose tissue [VAT], and liver attenuation [LA]) with aldosterone, plasma renin activity (renin), and aldosterone:renin ratio (ARR) were assessed in the Jackson Heart Study using adjusted linear regression models. Results: A 1-SD higher BMI was associated with a 4.8 % higher aldosterone, 9.4 % higher renin, and 5.0 % lower ARR (all p < 0.05). Log-leptin had the largest magnitude of association with renin (30.2 % higher) and ARR (9.6 % lower), while the strongest association of aldosterone existed for log-LAR (15.3 % higher) (all 1-SD, p < 0.05). SAT was only associated with renin. VAT was associated with higher aldosterone, renin, and ARR. Liver fat was associated with aldosterone and renin, but not ARR. Associations of WC, BMI, and SAT with aldosterone were greater in men while the association with VAT was greater in women (p-interactions < 0.05). Conclusion: Multiple measures of adiposity are associated with the RAAS in AAs. Further studies should examine the role of RAAS in obesity-driven cardiometabolic diseases.

The role of aldosterone and ideal cardiovascular health in incident cardiovascular disease: The Jackson heart study.

Background: Higher levels of ideal cardiovascular health (ICH) are associated with lower levels of aldosterone and incidence of cardiovascular disease (CVD). However, the degree to which aldosterone mediates the association between ICH and CVD incidence has not been explored. Thus, we investigated the mediational role of aldosterone in the association of 5 components of ICH (cholesterol, body mass index (BMI), physical activity, diet and smoking) with incident CVD and the mediational role of blood pressure (BP) and glucose in the association of aldosterone with incident CVD in a cohort of African Americans (AA). Methods: The Jackson Heart Study is a prospective cohort of AAs adults with data on CVD outcomes. Aldosterone, ICH metrics and baseline characteristics were collected at exam 1 (2000-2004). ICH score was developed by summing 5 ICH metrics (smoking, dietary intake, physical activity, BMI, and total cholesterol) and grouped into two categories (0-2 and ≥3 metrics). Incident CVD was defined as stroke, coronary heart disease, or heart failure. Cox proportional hazard regression models were used to model the association of categorical ICH score with incident CVD. The R Package Mediation was utilized to examine: 1) The mediational role of aldosterone in the association of ICH with incident CVD and 2) The mediational role of blood pressure and glucose in the association of aldosterone with incident CVD. Results: Among 3,274 individuals (mean age: 54±12.4 years, 65% female), there were 368 cases of incident CVD over a median of 12.7 years. The risk of incident CVD was 46% lower (HR: 0.54; 95%CI 0.36, 0.80) in those with ≥3 ICH metrics at baseline compared to 0-2. Aldosterone mediated 5.4% (p = 0.006) of the effect of ICH on incident CVD. A 1-unit increase in log-aldosterone was associated with a 38% higher risk of incident CVD (HR 1.38, 95%CI: 1.19, 1.61) with BP and glucose mediating 25.6% (p<0.001) and 4.8% (p = 0.048), respectively. Conclusion: Aldosterone partially mediates the association of ICH with incident CVD and both blood pressure and glucose partially mediate the association of aldosterone with incident CVD, emphasizing the potential importance of aldosterone and ICH in risk of CVD among AAs.

RCAN1-4 is a thyroid cancer growth and metastasis suppressor.

Metastasis suppressors are key regulators of tumor growth, invasion, and metastases. Loss of metastasis suppressors has been associated with aggressive tumor behaviors and metastatic progression. We previously showed that regulator of calcineurin 1, isoform 4 (RCAN1-4) was upregulated by the KiSS1 metastatic suppression pathway and could inhibit cell motility when overexpressed in cancer cells. To test the effects of endogenous RCAN1-4 loss on thyroid cancer in vivo, we developed RCAN1-4 knockdown stable cells. Subcutaneous xenograft models demonstrated that RCAN1-4 knockdown promotes tumor growth. Intravenous metastasis models demonstrated that RCAN1-4 loss promotes tumor metastases to the lungs and their subsequent growth. Finally, stable induction of RCAN1-4 expression reduced thyroid cancer cell growth and invasion. Microarray analysis predicted that nuclear factor, erythroid 2-like 3 (NFE2L3) was a pivotal downstream effector of RCAN1-4. NFE2L3 overexpression was shown to be necessary for RCAN1-4-mediated enhanced growth and invasiveness and NEF2L3 overexpression independently increased cell invasion. In human samples, NFE2L3 was overexpressed in TCGA thyroid cancer samples versus normal tissues and NFE2L3 overexpression was demonstrated in distant metastasis samples from thyroid cancer patients. In conclusion, we provide the first evidence to our knowledge that RCAN1-4 is a growth and metastasis suppressor in vivo and that it functions in part through NFE2L3.