Rationale & Objective

The safety of intensive blood pressure (BP) targets is controversial for persons with chronic kidney disease (CKD). We studied the effects of hypertension treatment on cerebral perfusion and structure in individuals with and without CKD.

Study Design

Neuroimaging substudy of a randomized trial.

Setting & Participants

A subset of participants in the Systolic Blood Pressure Intervention Trial (SPRINT) who underwent brain magnetic resonance imaging studies. Presence of baseline CKD was assessed by estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio (UACR).

Intervention

Participants were randomly assigned to intensive (systolic BP <120 mm Hg) versus standard (systolic BP <140 mm Hg) BP lowering.

Outcomes

The magnetic resonance imaging outcome measures were the 4-year change in global cerebral blood flow (CBF), white matter lesion (WML) volume, and total brain volume (TBV).

Results

A total of 716 randomized participants with a mean age of 68 years were enrolled; follow-up imaging occurred after a median 3.9 years. Among participants with eGFR <60 mL/min/1.73 m² (n = 234), the effects of intensive versus standard BP treatment on change in global CBF, WMLs, and TBV were 3.38 (95% CI, 0.32 to 6.44) mL/100 g/min, −0.06 (95% CI, −0.16 to 0.04) cm³ (inverse hyperbolic sine-transformed), and −3.8 (95% CI, −8.3 to 0.7) cm³, respectively. Among participants with UACR >30 mg/g (n = 151), the effects of intensive versus standard BP treatment on change in global CBF, WMLs, and TBV were 1.91 (95% CI, −3.01 to 6.82) mL/100 g/min, 0.003 (95% CI, −0.13 to 0.13) cm³ (inverse hyperbolic sine-transformed), and −7.0 (95% CI, −13.3 to −0.3) cm³, respectively. The overall treatment effects on CBF and TBV were not modified by baseline eGFR or UACR; however, the effect on WMLs was attenuated in participants with albuminuria (P = 0.04 for interaction).

Limitations

Measurement variability due to multisite design.

Conclusions

Among adults with hypertension who have primarily early kidney disease, intensive versus standard BP treatment did not appear to have a detrimental effect on brain perfusion or structure. The findings support the safety of intensive BP treatment targets on brain health in persons with early kidney disease.

Funding

SPRINT was funded by the National Institutes of Health (including the National Heart, Lung, and Blood Institute; the National Institute of Diabetes and Digestive and Kidney Diseases; the National Institute on Aging; and the National Institute of Neurological Disorders and Stroke), and this substudy was funded by the National Institutes of Diabetes and Digestive and Kidney Diseases.

Trial Registration

SPRINT was registered at ClinicalTrials.gov with study number NCT01206062.

中文翻译：

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肾脏疾病、高血压治疗、脑灌注和结构

理由和目标

对于慢性肾病 (CKD) 患者来说，强化血压 (BP) 目标的安全性存在争议。我们研究了高血压治疗对患有和不患有 CKD 个体的脑灌注和结构的影响。

学习规划

随机试验的神经影像学子研究。

背景及参与者

收缩压干预试验 (SPRINT) 的一部分参与者接受了脑部磁共振成像研究。通过估计肾小球滤过率 (eGFR) 和尿白蛋白肌酐比值 (UACR) 评估基线 CKD 的存在。

干涉

参与者被随机分配至强化降压组（收缩压<120 mm Hg）组和标准降压组（收缩压<140 mm Hg）组。

结果

磁共振成像结果指标是全脑血流量 (CBF)、白质病变 (WML) 体积和总脑体积 (TBV) 的 4 年变化。

结果

共有 716 名随机参与者入组，平均年龄为 68 岁；中位 3.9 年后进行随访影像学检查。^{在 eGFR <60 mL/min/1.73 m 2}的参与者中(n = 234)，强化血压治疗与标准血压治疗对整体 CBF、WML 和 TBV 变化的影响为 3.38 (95% CI，0.32 至 6.44) mL/分别为100 g/min、-0.06（95% CI，-0.16至0.04）cm ³（反双曲正弦变换）和-3.8（95% CI，-8.3至0.7）cm ³。在 UACR > 30 mg/g 的参与者中 (n = 151)，强化血压治疗与标准血压治疗对整体 CBF、WML 和 TBV 变化的影响为 1.91 (95% CI，-3.01 至 6.82) mL/100 g/分钟，分别为0.003（95％CI，-0.13至0.13）cm ³（反双曲正弦变换）和-7.0（95％CI，-13.3至-0.3）cm ³。CBF 和 TBV 的总体治疗效果不受基线 eGFR 或 UACR 的影响；然而，对于患有白蛋白尿的参与者，对 WML 的影响减弱（ 交互作用P = 0.04）。

局限性

多站点设计导致的测量变化。

结论

在主要患有早期肾脏疾病的成人高血压患者中，强化血压治疗与标准血压治疗相比似乎并未对大脑灌注或结构产生不利影响。研究结果支持针对早期肾病患者大脑健康的强化血压治疗的安全性。

资金

SPRINT 由美国国立卫生研究院（包括国家心肺血液研究所、国家糖尿病、消化和肾脏疾病研究所、国家老龄化研究所、国家神经疾病和中风研究所）资助，这项子研究由美国国立糖尿病、消化和肾脏疾病研究所资助。

试用注册

SPRINT 已在 ClinicalTrials.gov 注册，研究编号为 NCT01206062。