The Role of Sensory Innervation in Homeostatic and Injury-Induced Corneal Epithelial Renewal.

The cornea is the window through which we see the world. Corneal clarity is required for vision, and blindness occurs when the cornea becomes opaque. The cornea is covered by unique transparent epithelial cells that serve as an outermost cellular barrier bordering between the cornea and the external environment. Corneal sensory nerves protect the cornea from injury by triggering tearing and blink reflexes, and are also thought to regulate corneal epithelial renewal via unknown mechanism(s). When protective corneal sensory innervation is absent due to infection, trauma, intracranial tumors, surgery, or congenital causes, permanent blindness results from repetitive epithelial microtraumas and failure to heal. The condition is termed neurotrophic keratopathy (NK), with an incidence of 5:10,000 people worldwide. In this report, we review the currently available therapeutic solutions for NK and discuss the progress in our understanding of how the sensory nerves induce corneal epithelial renewal.

Pravastatin and cardiovascular outcomes stratified by baseline eGFR in the lipid- lowering component of ALLHAT.

BACKGROUND/AIMS: The role of statins in preventing cardiovascular outcomes in patients with chronic kidney disease (CKD) is unclear. This paper compares cardiovascular outcomes with pravastatin vs. usual care, stratified by baseline estimated glomerular filtration rate (eGFR). METHODS: Post-hoc analyses of a prospective randomized open-label clinical trial; 10,151 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (lipid-lowering component) were randomized to pravastatin 40 mg/day or usual care. Mean follow-up was 4.8 years. RESULTS: Through Year 6, total cholesterol declined in pravastatin (-20.7%) and usualcare groups (-11.2%). Use of statin therapy in the pravastatin group was 89.8% (Year 2) and 87.0% (Year 6). Usual-care group statin use increased from 8.2% (Year 2) to 23.5% (Year 6). By primary intention-to-treat analyses, no significant differences were seen between groups for coronary heart disease (CHD), total mortality or combined cardiovascular disease; findings were consistent across eGFR strata. In exploratory "as-treated" analyses (patients actually using pravastatin vs. not using), pravastatin therapy was associated with lower mortality (HR = 0.76 (0.68 - 0.85), p<0.001) and lover CHD (HR=0.84 (0.73-0.97), p=0.01), but not combined cardiovascular disease (HR=0.95 (0.88-1.04), p=0.30). Total cholesterol reduction of 10 mg/dl from baseline to Year 2 was associated with 5% lower CHD risk. CONCLUSIONS: In hypertensive patients with moderate dyslipidemia, pravastatin was not superior to usual care in preventing total mortality or CHD independent of baseline eGFR level. However, exploratory "as-treated" analyses suggest improved mortality and CHD risk in participants using pravastatin, and decreased CHD events associated with achieved reduction in total cholesterol. Potential benefit from statin therapy may depend on degree of reduction achieved in total and LDL-cholesterol and adherence to therapy.

Cardiovascular risk assessment: addition of CKD and race to the Framingham equation.

BACKGROUND/AIMS: The value of the Framingham equation in predicting cardiovascular risk in African Americans and patients with chronic kidney disease (CKD) is unclear. The purpose of the study was to evaluate whether the addition of CKD and race to the Framingham equation improves risk stratification in hypertensive patients. METHODS: Participants in the ALLHAT were studied. Those randomized to doxazosin, older than 74 years, and those with a history of coronary heart disease were excluded. Two risk stratification models were developed using Cox proportional hazards models in a two-thirds developmental sample. The first model included the traditional Framingham risk factors. The second model included the traditional risk factors plus CKD, defined by estimated glomerular filtration rate categories, and stratification by race (black vs non-black). The primary outcome was a composite of fatal coronary heart disease, nonfatal myocardial infarction, coronary revascularization, and hospitalized angina. RESULTS: There were a total of 19,811 eligible subjects. In the validation cohort, there was no difference in C-statistics between the Framingham equation and the ALLHAT model including CKD and race. This was consistent across subgroups by race and sex and among those with CKD. One exception was among Non-Black women where the C-statistic was higher for the Framingham equation (0.68 vs 0.65, P = .02). In addition, net reclassification improvement was not significant for any subgroup based on race and sex, ranging from -5.5% to 4.4%. CONCLUSION: The addition of CKD status and stratification by race does not improve risk prediction in high-risk hypertensive patients.

Progression of kidney disease in moderately hypercholesterolemic, hypertensive patients randomized to pravastatin versus usual care: a report from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT).

BACKGROUND: Dyslipidemia is common in patients with chronic kidney disease. The role of statin therapy in the progression of kidney disease is unclear. STUDY DESIGN: Prospective randomized clinical trial, post hoc analyses. SETTING & PARTICIPANTS: 10,060 participants in the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (lipid-lowering component) stratified by baseline estimated glomerular filtration rate (eGFR): less than 60, 60 to 89, and 90 or greater mL/min/1.73 m(2). Mean follow-up was 4.8 years. INTERVENTION: Randomized; pravastatin, 40 mg/d, or usual care. OUTCOMES & MEASUREMENTS: Total, high-density lipoprotein, and low-density lipoprotein cholesterol; end-stage renal disease (ESRD), eGFR. RESULTS: Through year 6, total cholesterol levels decreased in the pravastatin (-20.7%) and usual-care groups (-11.2%). No significant differences were seen between groups for rates of ESRD (1.36 v 1.45/100 patient-years; P = 0.9), composite end points of ESRD and 50% or 25% decrease in eGFR, or rate of change in eGFR. Findings were consistent across eGFR strata. In patients with eGFR of 90 mL/min/1.73 m(2) or greater, the pravastatin arm tended to have a higher eGFR. LIMITATIONS: Proteinuria data unavailable, post hoc analyses, unconfirmed validity of the Modification of Diet in Renal Disease Study equation in normal eGFR range, statin drop-in rate in usual-care group with small cholesterol differential between groups. CONCLUSIONS: In hypertensive patients with moderate dyslipidemia and decreased eGFR, pravastatin was not superior to usual care in preventing clinical renal outcomes. This was consistent across the strata of baseline eGFR. However, benefit from statin therapy may depend on the degree of the cholesterol level decrease achieved.

Long-term renal and cardiovascular outcomes in Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT) participants by baseline estimated GFR.

BACKGROUND AND OBJECTIVES: CKD is common among older patients. This article assesses long-term renal and cardiovascular outcomes in older high-risk hypertensive patients, stratified by baseline estimated GFR (eGFR), and long-term outcome efficacy of 5-year first-step treatment with amlodipine or lisinopril, each compared with chlorthalidone. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: This was a long-term post-trial follow-up of hypertensive participants (n=31,350), aged ≥55 years, randomized to receive chlorthalidone, amlodipine, or lisinopril for 4-8 years at 593 centers. Participants were stratified by baseline eGFR (ml/min per 1.73 m(2)) as follows: normal/increased (≥90; n=8027), mild reduction (60-89; n=17,778), and moderate/severe reduction (<60; n=5545). Outcomes were cardiovascular mortality (primary outcome), total mortality, coronary heart disease, cardiovascular disease, stroke, heart failure, and ESRD. RESULTS: After an average 8.8-year follow-up, total mortality was significantly higher in participants with moderate/severe eGFR reduction compared with those with normal and mildly reduced eGFR (P<0.001). In participants with an eGFR <60, there was no significant difference in cardiovascular mortality between chlorthalidone and amlodipine (P=0.64), or chlorthalidone and lisinopril (P=0.56). Likewise, no significant differences were observed for total mortality, coronary heart disease, cardiovascular disease, stroke, or ESRD. CONCLUSIONS: CKD is associated with significantly higher long-term risk of cardiovascular events and mortality in older hypertensive patients. By eGFR stratum, 5-year treatment with amlodipine or lisinopril was not superior to chlorthalidone in preventing cardiovascular events, mortality, or ESRD during 9-year follow-up. Because data on proteinuria were not available, these findings may not be extrapolated to proteinuric CKD.

Blood pressure control in Hispanics in the antihypertensive and lipid-lowering treatment to prevent heart attack trial.

Historically, blood pressure control in Hispanics has been considerably less than that of non-Hispanic whites and blacks. We compared determinants of blood pressure control among Hispanic white, Hispanic black, non-Hispanic white, and non-Hispanic black participants (N=32 642) during follow-up in a randomized, practice-based, active-controlled trial. Hispanic blacks and whites represented 3% and 16% of the cohort, respectively; 33% were non-Hispanic black and 48% were non-Hispanic white. Hispanics were less likely to be controlled (<140/90 mm Hg) at enrollment, but within 6 to 12 months of follow-up, Hispanics had a greater proportion <140/90 mm Hg compared with non-Hispanics. At 4 years of follow-up, blood pressure was controlled in 72% of Hispanic whites, 69% of Hispanic blacks, 67% of non-Hispanic whites, and 59% of non-Hispanic blacks. Compared with non-Hispanic whites, Hispanic whites had a 20% greater odds of achieving BP control by 2 years of follow-up (odds ratio: 1.20; 95% CI: 1.10 to 1.31) after controlling for demographic variables and comorbidities, Hispanic blacks had a similar odds of achieving BP control (odds ratio: 1.04; 95% CI: 0.86 to 1.25), and non-Hispanic blacks had a 27% lower odds (odds ratio: 0.73; 95% CI: 0.69 to 0.78). We conclude that in all patients high levels of blood pressure control can be achieved with commonly available medications and that Hispanic ethnicity is not associated with inferior control in the setting of a clinical trial in which hypertensive patients had equal access to medical care, and medication was provided at no cost.