Creatine kinase, energy reserve, and hypertension: from bench to bedside

Real-World Evidence of Indapamide-Induced Rhabdomyolysis: A Retrospective Analysis of Electronic Health Records

PURPOSE

Previous research and pharmacovigilance monitoring activities have suggested a potential association between indapamide use and rhabdomyolysis. This study aims to investigate the potential causal relationship between the use of indapamide and rhabdomyolysis.

METHODS

A case-control study conducted using electronic health records data, between July 1, 2016 and December 31, 2022. Patients who have rhabdomyolysis event (cases) were matched to four controls bases on age, gender, and date. We examined the odds for indapamide exposure through three risk periods: current use, recent use, and former. The study outcome was ascertained through the presence of CK level over 1000 U/L (i.e., rhabdomyolysis event). Subsequently, a multivariable conditional logistic regression analysis was utilized to assess the causal association of indapamide exposure on the likelihood of developing rhabdomyolysis, while accounting for potential confounding variables.

RESULTS

The study population consisted of 2965 cases and 11 860 controls. The results of the conditional logistic regression analysis indicated a lack of association between exposure to indapamide for the current users with an odds ratio (OR) of 0.6 (95% confidence intervals (CI): 0.39-1.05). The odds of recent indapamide use among cases was lower than controls (OR 0.2; 95% CI: 0.14-0.47). Lastly, the OR for former use of indapamide was 0.1 (95% CI: 0.07-0.23).

CONCLUSIONS

In this study, we did not find association between indapamide use and rhabdomyolysis regardless timing of exposure.

Time-restricted eating with or without a low-carbohydrate diet improved myocardial status and thyroid function in individuals with metabolic syndrome: secondary analysis of a randomized clinical trial

BACKGROUND

Obesity and metabolic syndrome (MetS) have become urgent worldwide health problems, predisposing patients to unfavorable myocardial status and thyroid dysfunction. Low-carbohydrate diet (LCD) and time-restricted eating (TRE) have been confirmed to be effective methods for weight management and improving MetS, but their effects on the myocardium and thyroid are unclear.

METHODS

We conducted a secondary analysis in a randomized clinical diet-induced weight-loss trial. Participants (N = 169) diagnosed with MetS were randomized to the LCD group, the 8 h TRE group, or the combination of the LCD and TRE group for 3 months. Myocardial enzymes and thyroid function were tested before and after the intervention. Pearson's or Spearman's correlation was assessed between functions of the myocardium and thyroid and cardiometabolic parameters at baseline.

RESULTS

A total of 162 participants who began the trial were included in the intention-to-treat (ITT) analysis, and 57 participants who adhered to their assigned protocol were involved in the per-protocol (PP) analysis. Relative to baseline, lactate dehydrogenase, creatine kinase MB, hydroxybutyrate dehydrogenase, and free triiodothyronine (FT3) declined, and free thyroxine (FT4) increased after all 3 interventions (both analyses). Creatine kinase (CK) decreased only in the TRE (- 18 [44] U/L, P < 0.001) and combination (- 22 [64] U/L, P = 0.003) groups (PP analysis). Thyrotropin (- 0.24 [0.83] μIU/mL, P = 0.011) and T3 (- 0.10 ± 0.04 ng/mL, P = 0.011) decreased in the combination group (ITT analysis). T4 (0.82 ± 0.39 μg/dL, P = 0.046), thyroglobulin antibodies (TgAb, 2 [1] %, P = 0.021), and thyroid microsomal antibodies (TMAb, 2 [2] %, P < 0.001) increased, while the T3/T4 ratio (- 0.01 ± 0.01, P = 0.020) decreased only in the TRE group (PP analysis). However, no significant difference between groups was observed in either analysis. At baseline, CK was positively correlated with the visceral fat area. FT3 was positively associated with triglycerides and total cholesterol. FT4 was negatively related to insulin and C-peptide levels. TgAb and TMAb were negatively correlated with the waist-to-hip ratio.

CONCLUSIONS

TRE with or without LCD confers remarkable metabolic benefits on myocardial status and thyroid function in subjects with MetS.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04475822.

Development and validation of a nomogram for assessment postoperative sodium disturbance in PAs patients: a retrospective cohort study

Background

Pituitary adenomas (PAs) are neuroendocrine tumors located in the sellar region. Surgery, being the primary treatment option for most PAs, is known to cause disruptions in sodium metabolism.

Objective

To develop and validate a nomogram for assessment the incidence of postoperative sodium disturbance (SD) in patients with PAs.

Methods

In this retrospective study, 208 patients with PAs who underwent resection surgery between 2013 and 2020 were included. Various demographic characteristics, clinical features and laboratory data were analyzed as potential predictors of postoperative sodium disturbance (SD). LASSO regression were used to identify independent preoperative variables associated with SD. Logistic regression was employed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). A nomogram was constructed to visualize these results and evaluated using metrics such as the area under the curve (AUC) for discrimination, the Hosmer-Lemeshow test for calibration and decision curve for usefulness assessment.

Results

The incidence of SD was 44.23% (92 cases out of 208). Six preoperative factors, including sex, types of PAs, phosphocreatine kinase (CK), serum iron (Fe), free fatty acids (NEFA) and mean corpuscular volume (MCV), were identified for constructing a predictive nomogram. The nomogram showed high accuracy, with AUC values of 0.851 (95% CI [0.799-0.923]) and 0.771 (95% CI [0.681-0.861]) in the training and validation datasets, respectively. Calibration assessment and decision curve analysis confirmed its good agreement and clinical utility.

Conclusion

A practical and effective nomogram for predicting SD after PAs surgery is presented in this study.

Ultrastructural changes in resistance arterioles of normotensive and hypertensive premenopausal women with uterine fibroids

The association between uterine smooth muscle fibroids and systemic arterial hypertension is poorly understood. Therefore, we explored possible concomitant myocyte pathology of systemic resistance-sized arterioles (200 to 400 μm), isolated from omental samples donated by 19 women (mean age 42 y; SE 1) undergoing fibroid surgery. Vessels of 17 women (8 hypertensives) were available for transmission electron microscopy. We found ultrastructural vessel wall abnormalities in all patients, albeit with greater severity in hypertensives. In the endothelium, this ranged from moderate mitochondrial and endoplasmic reticulum stress in normotensives, to necrosis and sloughing in hypertensives. Myocyte-like cells were observed to migrate across the internal elastic lamina, with isolated subendothelial myocytes in normotensives, and focal subendothelial multicellular aggregates or myo-intimal "cushions" in hypertensives. Medial myocytes of all patients showed abnormalities similar to fibroids, with dilated sarco-endoplasmic reticulum, elongated mitochondria, and myofilament loss involving focal areas or entire cells. To our knowledge, the first study on the ultrastructure of systemic resistance arterioles of women with fibroids indicates that severe abnormalities are present that likely affect blood pressure regulation. Whether these perturbations are induced by fibroids, or represent systemic pathology that affects myocytes of both uterine and vascular tissue warrants further exploration.

Correlative study on heavy metal-induced oxidative stress and hypertension among the rural population of Malwa Region of Punjab, India

Heavy metal-induced toxicity contributes to the progression of various metabolic disorders and possible mechanisms involved in disease progression are not well established. In this study, the correlation of  heavy metal exposure and  hypertension have been demonstrated. The results showed that in hypertensive subjects, the lipid profiles (triglycerides, LDL-C, HDL-C, and total cholesterol) and cardiac markers (CK-MB and LDH) were altered abruptly. As a consequence of heavy- induced oxidative stress, the oxidants (TBARS and protein carbonyls) and antioxidants (SOD, GSH, and TAC) were significantly increased and decreased, respectively in hypertension subjects. The concentrations of heavy metals (Pb, Cd, and As) exceeded the permissible limits in hypertensive subjects. The Nrf-2 genotyping indicated that heavy metals may induce mutations at molecular level. The results of correlation analysis revealed that the heavy metals interact with cellular components and interfere with metabolic processes which then results in disturbed lipid profile, enhanced oxidative stress, and reduced antioxidant status. The current study systematically estimated the association of hair and nail heavy metal concentrations with hypertension among the population residing in the Malwa region of Punjab. The proposed study highlighted that heavy metals act as a silent risk factor in the hypertension progression in the population of Malwa region. Future studies are required to confirm current findings and further scrutinize the effect of heavy metals exposure in early adulthood, early, and late mid-life to develop metabolic complications such as hypertension.

Effect of Copper Nanoparticles in the Diet of WKY and SHR Rats on the Redox Profile and Histology of the Heart, Liver, Kidney, and Small Intestine

The aim of this experiment was to test the effect of the partial or complete replacement of traditional CuCO₃ in the diet of rats with copper nanoparticles (CuNPs) on the biochemical parameters, redox status, and histomorphometry of their tissues. Normotensive male Wistar–Kyoto rats (WKY) were allocated to three groups. Three analogous groups of spontaneously hypertensive rats (SHR) were also formed. The WKY and SHR rats received copper in a standard daily dose—6.5 mg/kg CuCO₃ or CuNPs (100% replacement) or 3.25 mg/kg CuCO₃ plus 3.25 mg/kg CuNPs (50% replacement)—for 8 weeks. Next, blood, heart, small intestine, liver, and kidney samples were collected. The activity of alanine aminotransferase, aspartate aminotransferase, creatine kinase, and gamma-glutamyl transferase and the content of creatinine and urea acid were measured in the plasma. The collected tissues were subjected to a histological evaluation, and redox status parameters (catalase and superoxide dismutase activity, malondialdehyde and glutathione content) were determined. The replacement of CuCO₃ with CuNPs in the diet may exacerbate the negative changes induced by hypertension in the heart, liver, and intestines. However, it seems that it is only in the case of the liver where the observed changes may be due to an increase in oxidative reactions resulting from the inclusion of CuNPs.

Plasma creatine concentration is associated with incident hypertension in a cohort enriched for the presence of high urinary albumin concentration: the Prevention of Renal and Vascular Endstage Disease study

OBJECTIVE

: Hypertension is a major risk factor for cardiovascular disease, kidney disease, and premature death. Increased levels of creatine kinase are associated with development of hypertension. However, it is unknown if creatine, a substrate of CK, is associated with the development of hypertension. We therefore, aimed to investigate the association between plasma creatine concentration and incident hypertension.

METHODS

We measured fasting plasma creatine concentrations by nuclear magnetic resonance spectroscopy in participants of the population-based PREVEND study. The study outcome was incident hypertension, defined as either a SBP of at least 140 mmHg, a DBP of at least 90 mmHg, or the new usage of antihypertensive drugs. Participants with hypertension at baseline were excluded.

RESULTS

We included 3135 participants (46% men) aged 49 ± 10 years. Mean plasma creatine concentrations were 36.2 ± 17.5 μmol/l, with higher concentrations in women than in men (42.2 ± 17.6 versus 29.2 ± 17.6 μmol/l; P < 0.001). During a median of 7.1 [interquartile range: 3.6-7.6] years of follow-up, 927 participants developed incident hypertension. Higher plasma creatine concentrations were associated with an increased risk of incident hypertension [HR per doubling of plasma creatine: 1.21 (95% confidence interval: 1.10-1.34); P < 0.001], which remained significant after adjustment for potential confounders. Sex-stratified analyses demonstrated higher plasma creatine that was independently associated with an increased risk of incident hypertension in men [hazard ratio: 1.26 (95% CI 1.11-1.44); P < 0.001], but not in women (hazard ratio: 1.13 (95% CI 0.96-1.33); P = 0.14]. Causal pathway analyses demonstrate that the association was not explained by sodium or protein intake.

CONCLUSION

Higher plasma creatine is associated with an increased risk of hypertension in men. Future studies are warranted to determine the underlying mechanisms.

Paradoxical Increase in Body Mass Induced by Beta-Guanidinopropionic Acid in Juvenile Spontaneously Hypertensive Rats

Background

The adenosine triphosphate (ATP) regenerating enzyme creatine kinase (CK) is intimately involved in blood pressure generation. Consequently, the creatine transporter and CK inhibitor beta-guanidinopropionic acid (GPA) successfully reduced blood pressure in 16-week-old spontaneously hypertensive rats (SHR), but GPA may cause growth retardation in juvenile mammals. This report considers a serendipity observation of paradoxical growth increase after using GPA to prevent hypertension in three-week-old SHR.

Methods

Implementing the “Animal Research: Reporting of In Vivo Experiments” (ARRIVE) guideline, male, three-week-old spontaneously hypertensive rats (N=22) were randomly assigned to standard soy-based (creatine-free) chow with GPA 0.1% vs control chow during four weeks (primary, t=4w) or six weeks of treatment (t=6w). Blood pressure measured by the tail-cuff method was the main outcome. Other outcomes included body mass and contractility characteristics of isolated arteries.

Results 

Body mass at baseline was 28.4 (SE 0.71) g (n=22). With similar food intake/100 gram animal in both groups, GPA-treated rats (n=11) developed a strikingly larger body size and mass: t=4w, GPA 110.4 g (3.7) vs controls (n=11) 65.0 g (4.8) (+69.8%; p<0.001); t=6w, GPA 154.3 (4.7) vs controls 68.0 (4.7) g. There were no significant differences in cardiovascular parameters including blood pressure.

Discussion

An unexpected increase in body mass and size without concurrent blood pressure increase was observed in juvenile SHR on GPA vs control soy-based chow. It is speculated that the partial creatine agonist activity of GPA contributed to these effects. Further studies are needed to confirm these findings and better understand the impact of modulating energy metabolism in juvenile hypertension-prone mammals.

African Ancestry vs. Creatine Kinase to Predict Hypertension Control: Time for a Change?

BACKGROUND

African ancestry patients are considered separately in hypertension guidelines because of more severe hypertension that is presumably harder to control. However, despite the perceived benefit in reducing health disparities, racial profiling in medicine is increasingly criticized for its potential of bias and stereotyping. Therefore, we studied whether creatine kinase (CK), an ATP-regenerating enzyme that enhances vascular contractility and sodium retention, could serve as a more proximate causal parameter of therapy failure than race/ancestry.

METHODS

In a random multiethnic population sample, we compared the performance of African ancestry vs. resting plasma CK as predictors of treated uncontrolled hypertension. Difference in area under the receiver operating curve (AUC) was the primary outcome.

RESULTS

We analyzed 1,405 persons of African, Asian, and European ancestry (40.2% men, mean age 45.5 years, SE 0.2). Hypertension prevalence was 39% in African vs. 29% in non-African ancestry participants vs. 41% and 27% by high and low CK tertiles. Control rates of treated patients were similar by ancestry (African ancestry patients 40%, non-African ancestry 41%; P = 0.84), but 27% vs. 53% in patients with high vs. low CK (22% vs. 67% in African and 32% vs. 52% in non-African participants). AUC was 0.51 [0.41-0.60] for African ancestry vs. 0.64 [0.55-0.73] for log CK (P = 0.02).

CONCLUSIONS

In contrast to African ancestry, CK might identify hypertensive patients at risk for therapy failure across different ancestry groups. Larger, prospective studies should establish whether resting plasma CK is clinically useful as an impartial method to help predict antihypertensive therapy failure.

Creatine kinase is associated with bleeding after myocardial infarction

BACKGROUND

The ADP-scavenging enzyme creatine kinase (CK) is reported to reduce ADP-dependent platelet activation. Therefore, we studied whether highly elevated CK after ST-elevation myocardial infarction (STEMI) is associated with bleeding.

METHODS

Data of the Thrombolysis in Myocardial Infarction Study Group phase II trial on the efficacy of angioplasty, following intravenous recombinant tissue-type plasminogen activator (rt-PA), are used to assess whether peak plasma CK (CKmax) is independently associated with adjudicated fatal or non-fatal bleeding (primary) and combined bleeding/all-cause mortality (secondary) in multivariable binomial logistic regression analysis, adjusting for baseline and treatment allocation covariates.

RESULTS

The included patients (n=3339, 82% men, 88% white, mean age 57 years, SE 0.2) had a history of angina pectoris (55%), hypertension (38%) and/or diabetes mellitus (13%). CKmax ranged from 16 to 55 890 IU/L (mean 2389 IU/L, SE 41), reached within 8 hours in 51% of the patients (93% within 24 hours). Adjudicated fatal/non-fatal bleeding occurred in 30% of the patients (respectively 26% in the low vs 34% in the high CK tertile), and bleeding/all-cause mortality in 35% (29% in the low vs 40% in the high CK tertile). In multivariable regression analysis, the adjusted OR for fatal/non-fatal bleeding (vs not bleeding and survival) was 2.6 (95% CI 1.8 to 3.7)/log CKmax increase, and 3.1 (2.2 to 4.4) for bleeding/all-cause mortality.

CONCLUSION

Highly elevated plasma CK after myocardial infarction might be an independent predictor of bleeding and haemorrhagic death. This biologically plausible association warrants further prospective study of the potential role of extracellular CK in ADP-dependent platelet activation and bleeding.

Creatine kinase during non-ST-segment elevation acute coronary syndromes is associated with major bleeding

BACKGROUND

It was recently reported that highly elevated plasma activity of the ADP-scavenging enzyme creatine kinase (CK), to >10 times the upper reference limit (URL), is independently associated with fatal or non-fatal bleeding during treatment for ST-segment elevation myocardial infarction (OR 2.6 (95% CI, 1.8 to 2.7)/log CK increase). Evidence indicates that CK attenuates ADP-dependent platelet aggregation. This study investigates whether moderately elevated CK in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is associated with major bleeding.

METHODS

The Thrombolysis In Myocardial Ischemia (TIMI) 3B trial compared recombinant tissue-type plasminogen activator (rt-PA) (35-80 mg) with placebo and early catheterisation with conservative management in patients with NSTE-ACS. Main outcomes of the current study are the independent association of peak plasma CK (CKmax) with adjudicated fatal or non-fatal major bleeding (primary) and with combined major bleeding, stroke and hospital death (secondary), with covariables including age, sex, body mass index, systolic blood pressure, creatinine and assignment to add-on rt-PA versus placebo. Discrimination was assessed with C-statistics.

RESULTS

The study included 1473 patients (66% men, 80% white, mean age 59 years, SE 0.3). CKmax ranged between 15 and 19 045 IU/L (mean (SE), 450 (24) IU/L; two times URL). Major bleeding occurred in 2.0% (mean age 65 (1.3) years; mean CKmax 1015 (319) IU/L; six times URL), and the combined outcome in 4.3% of the patients, adjusted OR per log CK increase, respectively, 3.1 (1.6 to 5.9) for major bleeding and 3.9 (2.5 to 6.1) for the combined outcome; C-index 0.8 for both outcomes. The association between CK and bleeding was independent of the use of thrombolytic therapy.

DISCUSSION

The presented data add to the existing evidence that proportionate to its plasma activity, the ADP-binding enzyme CK is strongly and independently associated with non-fatal and fatal major bleeding during treatment for NSTE-ACS. CK might increase the accuracy of prediction models for major bleeding in patients with NSTE-ACS.

TRIAL REGISTRATION NUMBER

NCT00000472.

Extracellular creatine kinase may modulate purinergic signalling

Extracellular purine nucleotides and nucleosides including ADP and ATP regulate a wide array of physiological processes including platelet aggregation, vasomotor responses and inflammation through specific purinergic receptors. In the recent years, a strong association has been reported between circulating cytoplasmic-type creatine kinase and adverse clinical outcomes such as major bleeding, hypertension and obesity. Therefore, it is proposed that extracellular CK may modulate purinergic signalling through its ADP binding and/or ATP-generating effect.

Structure and function of resistance arteries from BB-creatine kinase and ubiquitous Mt-creatine kinase double knockout mice

Increasing evidence indicates that the enzyme creatine kinase (CK) is intimately involved in microvascular contractility. The mitochondrial isoenzyme catalyses phosphocreatine synthesis from ATP, while cytoplasmic CK, predominantly the BB isoenzyme in vascular tissue, is tightly bound near myosin ATPase, where it favours ATP production from phosphocreatine to metabolically support vascular contractility. However, the effect of CK gene inactivation on microvascular function is hitherto unknown. We studied functional and structural parameters of mesenteric resistance arteries isolated from 5 adult male mice lacking cytoplasmic BB-CK and ubiquitous mitochondrial CK (CK-/-) vs 6 sex/age-matched controls. Using a Mulvany Halpern myograph, we assessed the acute maximum contractile force with 125 mM K⁺ and 10^-5 M norepinephrine, and the effect of two inhibitors, dinitrofluorobenzene, which inhibits phosphotransfer enzymes (0.1 μM), and the specific adenylate kinase inhibitor P1, P5-di(adenosine 5') pentaphosphate (10^-6 to 10^-5 M). WT and CK-/- did not significantly differ in media thickness, vascular elasticity parameters, or acute maximum contractile force. CK-/- arteries displayed greater reduction in contractility after dinitrofluorobenzene 38%; vs 14% in WT; and after AK inhibition, 14% vs 5.5% in WT, and displayed abnormal mitochondria, with a partial loss of the inner membrane. Thus, CK-/- mice display a surprisingly mild phenotype in vascular dysfunction. However, the mitochondrial abnormalities and greater effect of inhibitors on contractility may reflect a compromised energy metabolism. In CK-/- mice, compensatory mechanisms salvage energy metabolism, as described for other CK knock-out models.

CK (Creatine Kinase) Is Associated With Cardiovascular Hemodynamics: The HELIUS Study

The ATP-regenerating enzyme CK (creatine kinase) is strongly associated with blood pressure, which lowers upon experimental CK inhibition. The enzyme is thought to affect cardiovascular hemodynamics through enhanced systemic vascular resistance, stroke volume, and cardiac contractility, but data on these parameters are lacking. We hereby report hemodynamics by CK levels in the multiethnic, cross-sectional HELIUS study (Healthy Life in an Urban Setting). Physical examination included sitting brachial blood pressure and noninvasively assessed supine systemic vascular resistance, stroke volume, cardiac output, and cardiac contractility, which we associated with resting plasma CK. Data from 14 937 men and women (mean age, 43.3; SD, 12.9) indicated that per log CK increase, blood pressure increased with 20.2 (18.9-21.4) mm Hg systolic/13.0 (12.2-13.7) diastolic, an odds ratio for hypertension of 6.1 (5.1-7.2). Outcomes were similar by sex, body mass index, and ancestry, although higher blood pressures in men, with overweight/obesity, and West-African ancestry were partially explained by higher CK, with an adjusted increase in systolic/diastolic pressure of 10.5 (10.0-10.9)/6.4 (6.0-6.7) mm Hg per log CK increase. Systemic vascular resistance, stroke volume, cardiac output, and cardiac contractility (n=7876), increased by respectively 20%, 39%, 14%, and 23% SD per log CK increase. This study indicates that the association of CK with blood pressure likely results from an increase in systemic vascular resistance and stroke volume. These data expand the knowledge on the nature of hypertension associated with CK and may inform further experiments on CK inhibition as a means to lower blood pressure.

Gold nanoparticles potentiates N-acetylcysteine effects on neurochemicals alterations in rats after polymicrobial sepsis

Herein, we report the effect of gold nanoparticles (AuNP) and n-acetylcysteine (NAC) isolated or in association as important anti-inflammatory and antioxidant compounds on brain dysfunction in septic rats. Male Wistar rats after sham operation or caecal ligation and perforation (CLP) were treated with subcutaneously injection of AuNP (50 mg/kg) and/or NAC (20 mg/kg) or saline immediately and 12 h after surgery. Twenty-four hours after CLP, hippocampus and prefrontal cortex were obtained and assayed for myeloperoxidase (MPO) activity, cytokines, lipid peroxidation, protein carbonyls formation, mitochondrial respiratory chain, and CK activity. AuNP + NAC association decreased MPO activity and pro-inflammatory cytokines production, being more effective than NAC or AuNP isolated treatment. AuNP + NAC association and NAC isolated treatment decreased oxidative stress to lipids in both brain structures, while protein oxidation decreased only in the hippocampus of AuNP + NAC association-treated animals. Complex I activity was increased with AuNP + NAC association and NAC isolated in the hippocampus. Regarding CK activity, AuNP and AuNP + NAC association increased this marker in both brain structures after CLP. Our data provide the first experimental demonstration that AuNP and NAC association was able to reduce sepsis-induced brain dysfunction in rats by decreasing neuroinflammation, oxidative stress parameters, mitochondrial dysfunction and CK activity.

Creatine Kinase and Blood Pressure: A Systematic Review

Background: Hypertension is a main risk factor for premature death. Although blood pressure is a complex trait, we have shown that the activity of the ATP-generating enzyme creatine kinase (CK) is a significant predictor of blood pressure and of failure of antihypertensive drug therapy in the general population. In this report, we systematically review the evidence on the association between this new risk factor CK and blood pressure outcomes. Method: We used a narrative synthesis approach and conducted a systematic search to include studies on non-pregnant adult humans that address the association between plasma CK and blood pressure outcomes. We searched electronic databases and performed a hand search without language restriction. We extracted data in duplo. The main outcome was the association between CK and blood pressure as continuous measures. Other outcomes included the association between CK and blood pressure categories (normotension and hypertension, subdivided in treated controlled, treated uncontrolled, and untreated hypertension). Results: We retrieved 139 reports and included 11 papers from 10 studies assessing CK in 34,578 participants, men and women, of African, Asian, and European ancestry, aged 18 to 87 years. In 9 reports, CK was associated with blood pressure levels, hypertension (vs. normotension), and/or treatment failure. The adjusted increase in systolic blood pressure (mmHg/log CK increase) was reported between 3.3 [1.4 to 5.2] and 8.0 [3.3 to 12.7] and the odds ratio of hypertension with high vs. low CK ranged between 1.2 and 3.9. In addition, CK was a strong predictor of treatment failure in the general population, with an adjusted odds ratio of 3.7 [1.2 to 10.9]. Discussion: This systematic review largely confirms earlier reports that CK is associated with blood pressure and failure of antihypertensive therapy. Further work is needed to address whether this new risk factor is useful in clinical medicine.