BACKGROUND Hypertension is common in autosomal dominant polycystic kidney disease (ADPKD) and is associated with increased total kidney volume, activation of the renin–angiotensin–aldosterone system, and progression of kidney disease. METHODS In this double-blind, placebo-controlled trial, we randomly assigned 558 hypertensive participants with ADPKD (15 to 49 years of age, with an estimated glomerular filtration rate [GFR] >60 ml per minute per 1.73 m2 of body-surface area) to either a standard blood-pressure target (120/70 to 130/80 mm Hg) or a low blood-pressure target (95/60 to 110/75 mm Hg) and to either an angiotensin-converting–enzyme inhibitor (lisinopril) plus an angiotensin-receptor blocker (telmisartan) or lisinopril plus placebo. The primary outcome was the annual percentage change in the total kidney volume. RESULTS The annual percentage increase in total kidney volume was significantly lower in the low-blood-pressure group than in the standard-blood-pressure group (5.6% vs. 6.6%, P = 0.006), without significant differences between the lisinopril–telmisartan group and the lisinopril–placebo group. The rate of change in estimated GFR was similar in the two medication groups, with a negative slope difference in the short term in the low-blood-pressure group as compared with the standard-blood-pressure group (P<0.001) and a marginally positive slope difference in the long term (P = 0.05). The left-ventricular-mass index decreased more in the low-blood-pressure group than in the standard-blood-pressure group (−1.17 vs. −0.57 g per square meter per year, P<0.001); urinary albumin excretion was reduced by 3.77% with the low-pressure target and increased by 2.43% with the standard target (P<0.001). Dizziness and light-headedness were more common in the low-blood-pressure group than in the standard-blood-pressure group (80.7% vs. 69.4%, P = 0.002). CONCLUSIONS In early ADPKD, the combination of lisinopril and telmisartan did not significantly alter the rate of increase in total kidney volume. As compared with standard blood-pressure control, rigorous blood-pressure control was associated with a slower increase in total kidney volume, no overall change in the estimated GFR, a greater decline in the left-ventricular-mass index, and greater reduction in urinary albumin excretion.

Autosomal dominant polycystic kidney disease (ADPKD) often results in ESRD but with a highly variable course. Mutations to PKD1 or PKD2 cause ADPKD; both loci have high levels of allelic heterogeneity. We evaluated genotype-phenotype correlations in 1119 patients (945 families) from the HALT Progression of PKD Study and the Consortium of Radiologic Imaging Study of PKD Study. The population was defined as: 77.7% PKD1, 14.7% PKD2, and 7.6% with no mutation detected (NMD). Phenotypic end points were sex, eGFR, height-adjusted total kidney volume (htTKV), and liver cyst volume. Analysis of the eGFR and htTKV measures showed that the PKD1 group had more severe disease than the PKD2 group, whereas the NMD group had a PKD2-like phenotype. In both the PKD1 and PKD2 populations, men had more severe renal disease, but women had larger liver cyst volumes. Compared with nontruncating PKD1 mutations, truncating PKD1 mutations associated with lower eGFR, but the mutation groups were not differentiated by htTKV. PKD1 nontruncating mutations were evaluated for conservation and chemical change and subdivided into strong (mutation strength group 2 [MSG2]) and weak (MSG3) mutation groups. Analysis of eGFR and htTKV measures showed that patients with MSG3 but not MSG2 mutations had significantly milder disease than patients with truncating cases (MSG1), an association especially evident in extreme decile populations. Overall, we have quantified the contribution of genic and PKD1 allelic effects and sex to the ADPKD phenotype. Intrafamilial correlation analysis showed that other factors shared by families influence htTKV, with these additional genetic/environmental factors significantly affecting the ADPKD phenotype.

BACKGROUND Hypertension develops early in patients with autosomal dominant polycystic kidney disease (ADPKD) and is associated with disease progression. The renin–angiotensin–aldosterone system (RAAS) is implicated in the pathogenesis of hypertension in patients with ADPKD. Dual blockade of the RAAS may circumvent compensatory mechanisms that limit the efficacy of monotherapy with an angiotensin-converting–enzyme (ACE) inhibitor or angiotensin II–receptor blocker (ARB). METHODS In this double-blind, placebo-controlled trial, we randomly assigned 486 patients, 18 to 64 years of age, with ADPKD (estimated glomerular filtration rate [GFR], 25 to 60 ml per minute per 1.73 m2 of body-surface area) to receive an ACE inhibitor (lisinopril) and placebo or lisinopril and an ARB (telmisartan), with the doses adjusted to achieve a blood pressure of 110/70 to 130/80 mm Hg. The composite primary outcome was the time to death, end-stage renal disease, or a 50% reduction from the baseline estimated GFR. Secondary outcomes included the rates of change in urinary aldosterone and albumin excretion, frequency of hospitalizations for any cause and for cardiovascular causes, incidence of pain, frequency of ADPKD-related symptoms, quality of life, and adverse study-medication effects. Patients were followed for 5 to 8 years. RESULTS There was no significant difference between the study groups in the incidence of the composite primary outcome (hazard ratio with lisinopril–telmisartan, 1.08; 95% confidence interval, 0.82 to 1.42). The two treatments controlled blood pressure and lowered urinary aldosterone excretion similarly. The rates of decline in the estimated GFR, urinary albumin excretion, and other secondary outcomes and adverse events, including hyperkalemia and acute kidney injury, were also similar in the two groups. CONCLUSIONS Monotherapy with an ACE inhibitor was associated with blood-pressure control in most patients with ADPKD and stage 3 chronic kidney disease. The addition of an ARB did not alter the decline in the estimated GFR. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; HALT-PKD [Study B] ClinicalTrials.gov number, NCT01885559.)

Background In people with early autosomal dominant polycystic kidney disease (ADPKD) average total kidney volume (TKV) is three times normal and increases by an average of 5% per year despite seemingly normal glomerular filtration rate (GFR). We hypothesized that increased TKV would be a source of morbidity and diminished quality of life that would be worse in subjects with more advanced disease. Study Design Cross-sectional. Setting & Participants 1043 subjects with ADPKD, hypertension and a baseline estimated glomerular filtration rate (eGFR) >20 mL/min/1.73 m2. Predictors 1) eGFR 2) height-adjusted TKV (htTKV) in subjects with eGFR >60 mL/min/1.73 m2. Outcomes 36-Item Short Form Health Survey (SF-36) and the Wisconsin Brief Pain Survey. Measurements Questionnaires were self- administered. eGFR was estimated from serum creatinine using the CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration) equation. The htTKV was measured by MRI. Results Back pain was reported by 50% of subjects and 20% experienced it ‘often, usually, or always’. In subjects with early disease (eGFR >60 mL/min/1.73 m2) there was no association between pain and htTKV, except in patients with large kidneys (htTKV >1000 mL/m). Comparing across eGFR levels and including patients with eGFR <60 mL/min/ 1.73 m2, patients with eGFR 20–44 mL/min/1.73 m2 were significantly more likely to report that pain impacted on their daily lives and had lower SF-36 scores than patients with eGFR 45–60 and ≥60 mL/min/1.73 m2. Symptoms relating to abdominal fullness were reported by 20% of patients, and were significantly related with lower eGFR in women but not men. Limitations TKV and liver volume were not measured in subjects with eGFR <60 mL/min/1.73 m2. The number of patients with eGFR <30 mL/min/1.73 m2 is small. Causal inferences are limited by cross-sectional design. Conclusions Pain is a common early symptom in the course of ADPKD, although it is not related to kidney size in early disease (eGFR >60 mL/min/1.73 m2), except in individuals with large kidneys (htTKV >1000 mL/m). Symptoms relating to abdominal fullness and pain are greater in patients with more advanced (eGFR 20–45 mL/min/ 1.73 m2) disease and may be due to organ enlargement, especially in women. More research about the role of TKV in quality of life and outcomes of ADPKD patients is warranted.

Background and objectives: Two HALT PKD trials will investigate interventions that potentially slow kidney disease progression in hypertensive autosomal dominant polycystic kidney disease (ADPKD) patients. Studies were designed in early and later stages of ADPKD to assess the impact of intensive blockade of the renin-angiotensin-aldosterone system and level of BP control on progressive renal disease.Design, settings, participants, and measurements: PKD-HALT trials are multicenter, randomized, double-blind, placebocontrolled trials studying 1018 hypertensive ADPKD patients enrolled over 3 yr with 4 to 8 yr of follow-up. In study A, 548 participants, estimated GFR (eGFR) of >60 ml/min per 1. Results: This report describes design issues related to (1) novel endpoints such as kidney volume, (2) home versus office BP measures, and (3) the impact of RAAS inhibition on kidney and patient outcomes, safety, and quality of life.Conclusions: HALT PKD will evaluate potential benefits of rigorous BP control and inhibition of the renin-angiotensinaldosterone system on kidney disease progression in ADPKD.