Hurricanes pose a substantial risk to New England forest carbon stocks.

Nature-based climate solutions (NCS) are championed as a primary tool to mitigate climate change, especially in forested regions capable of storing and sequestering vast amounts of carbon. New England is one of the most heavily forested regions in the United States (>75% forested by land area), and forest carbon is a significant component of climate mitigation policies. Large infrequent disturbances, such as hurricanes, are a major source of uncertainty and risk for policies relying on forest carbon for climate mitigation, especially as climate change is projected to alter the intensity and extent of hurricanes. To date, most research into disturbance impacts on forest carbon stocks has focused on fire. Here, we show that a single hurricane in the region can down between 121 and 250 MMTCO2e or 4.6%-9.4% of the total aboveground forest carbon, much greater than the carbon sequestered annually by New England's forests (16 MMTCO2e year-1). However, emissions from hurricanes are not instantaneous; it takes approximately 19 years for downed carbon to become a net emission and 100 years for 90% of the downed carbon to be emitted. Reconstructing hurricanes with the HURRECON and EXPOS models across a range of historical and projected wind speeds, we find that an 8% and 16% increase in hurricane wind speeds leads to a 10.7- and 24.8-fold increase in the extent of high-severity damaged areas (widespread tree mortality). Increased wind speed also leads to unprecedented geographical shifts in damage, both inland and northward, into heavily forested regions traditionally less affected by hurricanes. Given that a single hurricane can emit the equivalent of 10+ years of carbon sequestered by forests in New England, the status of these forests as a durable carbon sink is uncertain. Understanding the risks to forest carbon stocks from disturbances is necessary for decision-makers relying on forests as a NCS.

Oxidative damage in the gastrocnemius predicts long-term survival in patients with peripheral artery disease.

Patients with peripheral artery disease (PAD) have increased mortality rates and a myopathy in their affected legs which is characterized by increased oxidative damage, reduced antioxidant enzymatic activity and defective mitochondrial bioenergetics. This study evaluated the hypothesis that increased levels of oxidative damage in gastrocnemius biopsies from patients with PAD predict long-term mortality rates. Oxidative damage was quantified as carbonyl adducts in myofibers of the gastrocnemius of PAD patients. The oxidative stress data were grouped into tertiles and the 5-year, all-cause mortality for each tertile was determined by Kaplan-Meier curves and compared by the Modified Peto test. A Cox-regression model was used to control the effects of clinical characteristics. Results were adjusted for age, sex, race, body mass index, ankle-brachial index, smoking, physical activity, and comorbidities. Of the 240 study participants, 99 died during a mean follow up of 37.8 months. Patients in the highest tertile of oxidative damage demonstrated the highest 5-year mortality rate. The mortality hazard ratios (HR) from the Cox analysis were statistically significant for oxidative damage (lowest vs middle tertile; HR = 6.33; p = 0.0001 and lowest vs highest; HR = 8.37; p < 0.0001). Survival analysis of a contemporaneous population of PAD patients identifies abundance of carbonyl adducts in myofibers of their gastrocnemius as a predictor of mortality rate independently of ankle-brachial index, disease stage and other clinical and myopathy-related covariates.

Metabolic and Bariatric Surgery Utilization Trends in the United States: Evidence From 2012 to 2021 National Electronic Medical Records Network.

Background: Bariatric surgery has evolved over the past 2 decades yet assessing trends of bariatric surgery utilization in the growing eligible population is lacking. Aim: This study aimed to update the trends in bariatric surgery utilization, changes in types of procedures performed, and the characteristics of patients who underwent bariatric surgery in the United States, using real-world data. Method: This retrospective descriptive observational study was conducted using the TriNetX, a federated electronic medical records network from 2012 to 2021, for adult patients 18 years old or older who had bariatric surgery. Descriptive statistical analysis was conducted to assess patients' demographics and characteristics. Annual secular trend analyses were conducted for the annual rate of bariatric surgery, and the specific procedural types and proportions of laparoscopic surgeries. Results: A steady increase in the number of procedures performed in the United States over the first 6 years of the study, a plateau for the following 2 years, and then a decline in 2020 and 2021 (during the coronavirus disease 2019 pandemic). The annual rate of bariatric surgery was lowest in 2012 at 59.2 and highest in 2018 at 79.6 surgeries per 100,000 adults. During the study period, 96.2% to 98.8% of procedures performed annually were conducted laparoscopically as opposed to the open technique. Beginning in 2012, the Roux-en-Y gastric bypass (RYGB) procedure fell to represent only 17.1% of cases in 2018, along with a sharp decline in the adjustable gastric band (AGB) procedure, replaced by a sharp increase in the sleeve gastrectomy (SG) procedure to represent over 74% of cases in 2018. Conclusions: Bariatric surgery utilization in the United States showed a moderate decline in the number of RYGB procedures, which was offset by a substantial increase in the number of SG procedures and a precipitous drop in the annual number of AGB procedures.

Intravascular ultrasound to aid in the diagnosis and revision of an intra-aortic pedicle screw: illustrative case.

BACKGROUND: Pedicle screw impingement on vessel walls has the potential for complications due to pulsatile effects and wall erosion. Artifacts from spinal instrumentation create difficulty in accurately evaluating this interface. The authors present the first case of intravascular ultrasound (IVUS) used to characterize a pedicle screw breach into the aortic lumen. OBSERVATIONS: A 21-year-old female with surgically corrected scoliosis underwent computed tomography angiography (CTA) 3 years postoperatively, which revealed a pedicle screw within the thoracic aorta lumen. Metal artifact distorted the CTA images, which prompted the decision to use intraoperative IVUS. The IVUS confirmed the noninvasive imaging findings and guided final decisions regarding aortic endograft size and location during spine hardware revision. LESSONS: For asymptomatic patients presenting with pedicle screws malpositioned in or near the aorta, treatment decisions revolve around the extent of vessel wall penetration. Intraluminal depth can be obscured by artifact on computed tomography or magnetic resonance imaging or inadequately evaluated by a transesophageal echocardiogram. In our intraoperative experience, IVUS confirmed the depth of vessel lumen violation by a single pedicle screw and no wall penetration by two additional screws of concern. This was useful in deciding on thoracic endovascular aortic repair graft size and landing zone and facilitated safe spinal instrumentation removal and revision.

What is the role of disturbance in catalyzing spatial shifts in forest composition and tree species biomass under climate change?

Mounting evidence suggests that climate change will cause shifts of tree species range and abundance (biomass). Abundance changes under climate change are likely to occur prior to a detectable range shift. Disturbances are expected to directly affect tree species abundance and composition, and could profoundly influence tree species spatial distribution within a geographical region. However, how multiple disturbance regimes will interact with changing climate to alter the spatial distribution of species abundance remains unclear. We simulated such forest demographic processes using a forest landscape succession and disturbance model (LANDIS-II) parameterized with forest inventory data in the northeastern United States. Our study incorporated climate change under a high-emission future and disturbance regimes varying with gradients of intensities and spatial extents. The results suggest that disturbances catalyze changes in tree species abundance and composition under a changing climate, but the effects of disturbances differ by intensity and extent. Moderate disturbances and large extent disturbances have limited effects, while high-intensity disturbances accelerate changes by removing cohorts of mid- and late-successional species, creating opportunities for early-successional species. High-intensity disturbances result in the northern movement of early-successional species and the southern movement of late-successional species abundances. Our study is among the first to systematically investigate how disturbance extent and intensity interact to determine the spatial distribution of changes in species abundance and forest composition.

Electrokinetic separation techniques for studying nano- and microplastics.

In recent years, microplastics have been found in seawater, soil, food, and even human blood and tissues. The ubiquity of microplastics is alarming, but the health and environmental impacts of microplastics are just beginning to be understood. Accordingly, sampling, separating, and quantifying exposure to microplastics to devise a total risk assessment is the focus of ongoing research. Unfortunately, traditional separation methods (i.e., size- and density-based methods) unintentionally exclude the smallest microplastics (<10 µm). Limited data about the smallest microplastics is problematic because they are likely the most pervasive and have distinct properties from their larger plastic counterparts. To that end, in this Perspective, we discuss using electrokinetic methods for separating the smallest microplastics. Specifically, we describe three methods for forming electric field gradients, discuss key results within the field for continuously separating microplastics, and lastly discuss research avenues which we deem critical for advancing electrokinetic separation platforms for targeting the smallest microplastics.

N and P constrain C in ecosystems under climate change: Role of nutrient redistribution, accumulation, and stoichiometry.

We use the Multiple Element Limitation (MEL) model to examine responses of 12 ecosystems to elevated carbon dioxide (CO2 ), warming, and 20% decreases or increases in precipitation. Ecosystems respond synergistically to elevated CO2 , warming, and decreased precipitation combined because higher water-use efficiency with elevated CO2 and higher fertility with warming compensate for responses to drought. Response to elevated CO2 , warming, and increased precipitation combined is additive. We analyze changes in ecosystem carbon (C) based on four nitrogen (N) and four phosphorus (P) attribution factors: (1) changes in total ecosystem N and P, (2) changes in N and P distribution between vegetation and soil, (3) changes in vegetation C:N and C:P ratios, and (4) changes in soil C:N and C:P ratios. In the combined CO2 and climate change simulations, all ecosystems gain C. The contributions of these four attribution factors to changes in ecosystem C storage varies among ecosystems because of differences in the initial distributions of N and P between vegetation and soil and the openness of the ecosystem N and P cycles. The net transfer of N and P from soil to vegetation dominates the C response of forests. For tundra and grasslands, the C gain is also associated with increased soil C:N and C:P. In ecosystems with symbiotic N fixation, C gains resulted from N accumulation. Because of differences in N versus P cycle openness and the distribution of organic matter between vegetation and soil, changes in the N and P attribution factors do not always parallel one another. Differences among ecosystems in C-nutrient interactions and the amount of woody biomass interact to shape ecosystem C sequestration under simulated global change. We suggest that future studies quantify the openness of the N and P cycles and changes in the distribution of C, N, and P among ecosystem components, which currently limit understanding of nutrient effects on C sequestration and responses to elevated CO2 and climate change.

Erroneous Central Venous Catheter Placement: Multidisciplinary Primary Surgical Repair of the Vertebral Artery.

Central venous catheters are a common practice in critical care medicine. These lines are of particular importance when a patient needs large volume resuscitation or medications that cannot be infused through a peripheral line. Even though central venous catheters are frequently utilized, they are associated with potentially significant risks that one must be aware of when attempting placement. The anatomy and pertinent complications are key for any healthcare professional to be aware of during this procedure. As such, vascular injury has been described in the literature, but vertebral artery injury and common repair techniques are less common. Primary repair of the second vertebral artery segment is infrequently detailed in the literature and this report describes pertinent case details and plan of action for identification and repair of iatrogenic vertebral artery injury following catheter placement.

Impaired microcirculatory function, mitochondrial respiration, and oxygen utilization in skeletal muscle of claudicating patients with peripheral artery disease.

Peripheral artery disease (PAD) is an atherosclerotic disease that impairs blood flow and muscle function in the lower limbs. A skeletal muscle myopathy characterized by mitochondrial dysfunction and oxidative damage is present in PAD; however, the underlying mechanisms are not well established. We investigated the impact of chronic ischemia on skeletal muscle microcirculatory function and its association with leg skeletal muscle mitochondrial function and oxygen delivery and utilization capacity in PAD. Gastrocnemius samples and arterioles were harvested from patients with PAD (n = 10) and age-matched controls (Con, n = 11). Endothelium-dependent and independent vasodilation was assessed in response to flow (30 µL·min-1), acetylcholine, and sodium nitroprusside (SNP). Skeletal muscle mitochondrial respiration was quantified by high-resolution respirometry, microvascular oxygen delivery, and utilization capacity (tissue oxygenation index, TOI) were assessed by near-infrared spectroscopy. Vasodilation was attenuated in PAD (P < 0.05) in response to acetylcholine (Con: 71.1 ± 11.1%, PAD: 45.7 ± 18.1%) and flow (Con: 46.6 ± 20.1%, PAD: 29.3 ± 10.5%) but not SNP (P = 0.30). Complex I + II state 3 respiration (P < 0.01) and TOI recovery rate were impaired in PAD (P < 0.05). Both flow and acetylcholine-mediated vasodilation were positively associated with complex I + II state 3 respiration (r = 0.5 and r = 0.5, respectively, P < 0.05). Flow-mediated vasodilation and complex I + II state 3 respiration were positively associated with TOI recovery rate (r = 0.8 and r = 0.7, respectively, P < 0.05). These findings suggest that chronic ischemia attenuates skeletal muscle arteriole endothelial function, which may be a key mediator for mitochondrial and microcirculatory dysfunction in the PAD leg skeletal muscle. Targeting microvascular dysfunction may be an effective strategy to prevent and/or reverse disease progression in PAD.NEW & NOTEWORTHY Ex vivo skeletal muscle arteriole endothelial function is impaired in claudicating patients with PAD, and this is associated with attenuated skeletal muscle mitochondrial respiration. In vivo skeletal muscle oxygen delivery and utilization capacity is compromised in PAD, and this may be due to microcirculatory and mitochondrial dysfunction. These results suggest that targeting skeletal muscle arteriole function may lead to improvements in skeletal muscle mitochondrial respiration and oxygen delivery and utilization capacity in claudicating patients with PAD.

Electrochemical pH regulation in droplet microfluidics.

We report a method for electrochemical pH regulation in microdroplets generated in a microfluidic device. The key finding is that controlled quantities of reagents can be generated electrochemically in moving microdroplets confined within a microfluidic channel. Additionally, products generated at the anode and cathode can be isolated within descendant microdroplets. Specifically, ∼5 nL water-in-oil microdroplets are produced at a T-junction and then later split into two descendant droplets. During splitting, floor-patterned microelectrodes drive water electrolysis within the aqueous microdroplets to produce H+ and OH-. This results in a change in the pHs of the descendant droplets. The droplet pH can be regulated over a range of 5.9 to 7.7 by injecting controlled amounts of charge into the droplets. When the injected charge is between -6.3 and 54.5 nC nL-1, the measured pH of the resulting droplets is within ±0.1 pH units of that predicted based on the magnitude of the injected charge. This technique can likely be adapted to electrogeneration of other reagents within microdroplets.

Emerald ash borer intensifies harvest regimes on private land.

Invasive forest insects have significant direct impacts on forest ecosystems and they are also generating new risks, uncertainties, and opportunities for forest landowners. The growing prevalence and inexorable spread of invasive insects across the United States, combined with the fact that the majority of the nation's forests are controlled by thousands of autonomous private landowners, raises an important question: To what extent will private landowners alter their harvest practices in response to insect invasions? Using a quasi-experimental design, we conducted a causal analysis to investigate the influence of the highly impactful emerald ash borer (EAB) on (1) annual probability of harvest; (2) intensity of harvest; and (3) diameter of harvested trees, for both ash and non-ash species on private land throughout the Midwest and mid-Atlantic regions of the United States. We found that EAB detection had a negative impact on annual harvest probability and a positive impact on harvest intensity, resulting in a net increase in harvested biomass. Furthermore, our estimates suggest that EAB detection will influence private landowners to harvest greater quantities of ash, relative to non-ash species. We also found that harvested trees in EAB-infested areas had smaller diameters, on average, compared with those unaffected by EAB. These results can help policymakers, forest managers, and extension programs to anticipate and better advise landowners and managers about their options and the associated outcomes for forests.

Elevated growth and biomass along temperate forest edges.

Fragmentation transforms the environment along forest edges. The prevailing narrative, driven by research in tropical systems, suggests that edge environments increase tree mortality and structural degradation resulting in net decreases in ecosystem productivity. We show that, in contrast to tropical systems, temperate forest edges exhibit increased forest growth and biomass with no change in total mortality relative to the forest interior. We analyze >48,000 forest inventory plots across the north-eastern US using a quasi-experimental matching design. At forest edges adjacent to anthropogenic land covers, we report increases of 36.3% and 24.1% in forest growth and biomass, respectively. Inclusion of edge impacts increases estimates of forest productivity by up to 23% in agriculture-dominated areas, 15% in the metropolitan coast, and +2% in the least-fragmented regions. We also quantify forest fragmentation globally, at 30-m resolution, showing that temperate forests contain 52% more edge forest area than tropical forests. Our analyses upend the conventional wisdom of forest edges as less productive than intact forest and call for a reassessment of the conservation value of forest fragments.

Filtering and continuously separating microplastics from water using electric field gradients formed electrochemically in the absence of buffer.

Here we use experiments and finite element simulations to investigate the electrokinetics within straight microchannels that contain a bipolar electrode and an unbuffered electrolyte solution. Our findings indicate that in the presence of a sufficiently high electric field, water electrolysis proceeds at the bipolar electrode and leads to variations in both solution conductivity and ionic current density along the length of the microchannel. The significance of this finding is twofold. First, the results indicate that both solution conductivity and ionic current density variations significantly contribute to yield sharp electric field gradients near the bipolar electrode poles. The key point is that ionic current density variations constitute a fundamentally new mechanism for forming electric field gradients in solution. Second, we show that the electric field gradients that form near the bipolar electrode poles in unbuffered solution are useful for continuously separating microplastics from water in a bifurcated microchannel. This result expands the potential scope of membrane-free separations using bipolar electrodes.

Claudicating patients with peripheral artery disease have meaningful improvement in walking speed after supervised exercise therapy.

OBJECTIVE: Supervised exercise therapy (SET) is a first-line treatment for patients with peripheral artery disease (PAD). The efficacy of SET is most commonly expressed by significant statistical improvement of parameters that do not clarify how each individual patient will benefit from SET. This study examined the minimal clinically important difference (MCID) in walking speed in claudicating patients with PAD after SET. METHODS: A total of 63 patients with PAD-related claudication (Fontaine stage II PAD) participated in a 6-month SET program. Self-selected walking speed was measured before and after SET. Distribution and anchor-based approaches were used to estimate the MCID for small and substantial improvement. The ability to walk one block and the ability to climb one flight of stairs questions were chosen as anchor questions from the Medical Outcomes Study 36-item Short Form questionnaire. Receiver operating characteristics curve analyses were performed to detect the threshold for MCID in walking speed after treatment. RESULTS: The distribution-based method estimated 0.03 m/s as a small improvement and 0.08 m/s as a substantial improvement after SET. Small and substantial improvements according to the anchor question walking one block were 0.05 m/s and 0.15 m/s, respectively. For the climbing one flight of stairs anchor question, 0.10 m/s was a small improvement. Receiver operating characteristics curve analyses identified an increase of 0.04 m/s and 0.03 m/s for improvement based on walking one block and climbing one flight of stairs, respectively. CONCLUSIONS: We report our findings for the MCID for walking speed among claudicating patients receiving SET. Claudicating patients who increase walking speed of 0.03 m/s or greater are more likely to experience a meaningful improvement in walking impairment than those who do not. The MCID reported in this study can serve as a benchmark for clinicians to develop goals and interpret clinically meaningful progress in the care of claudicating patients with PAD.

Cytokine signature of inflammation mediated by autoreactive Th-cells, in calf muscle of claudicating patients with Fontaine stage II peripheral artery disease.

Peripheral artery disease (PAD), a severe atherosclerotic condition primarily of the elderly, afflicts 200 million individuals, worldwide, and is associated with lower extremity myopathy. Circulating markers of inflammation have been linked to risk and severity of PAD but the contribution of local inflammation to myopathy remains unknown. We evaluated, by ELISA, calf muscle of PAD patients (N = 23) and control subjects (N = 18) for local expression of inflammatory cytokines including Granulocyte/Monocyte Colony-Stimulating Factor (GM-CSF), Interleukin 17A (IL-17A), Interferon ϒ (IFN-ϒ), tumor necrosis factor α (TNF-α), and Interleukin 6 (IL-6). One or more of these cytokines were expressed in nineteen patients and 2 controls and coordinated expression of GM-CSF, IL-17A, IFN-ϒ, and TNF-α, a signature of activated, MHC Class II dependent autoreactive Th-cells, was unique to 11 patients. GM-CSF is the central driver of tissue-damaging myeloid macrophages. Patients with this cytokine signature had a shorter (P= 0.017) Claudication Onset Distance (17 m) compared with patients lacking the signature (102 m). Transforming Growth Factor ß1 (TGFß1) and Chemokine Ligand 5 (CCL5) were expressed coordinately in all PAD and control muscles, independently of GM-CSF, IL-17A, IFN-ϒ, TNF-α, or IL-6. TGFß1 and CCL5 and their gene transcripts were increased in PAD muscle, consistent with increased age-associated inflammation in these patients. Serum cytokines were not informative of muscle cytokine expression. We have identified a cytokine profile of autoimmune inflammation in calf muscles of a significant proportion of claudicating PAD patients, in association with decreased limb function, and a second independent profile consistent with increased "inflammaging" in all PAD patients.

Co-designed Land-use Scenarios and their Implications for Storm Runoff and Streamflow in New England.

Landscape and climate changes have the potential to create or exacerbate problems with stormwater management, high flows, and flooding. In New England, four plausible land-use scenarios were co-developed with stakeholders to give insight to the effects on ecosystem services of different trajectories of socio-economic connectedness and natural resource innovation. With respect to water, the service of greatest interest to New England stakeholders is the reduction of stormwater and flooding. To assess the effects of these land-use scenarios, we applied the Soil and Water Assessment Tool to two watersheds under two climates. Differences in land use had minimal effects on the water balance but did affect high flows and the contribution of storm runoff to streamflow. For most scenarios, the effect on high flows was small. For one scenario-envisioned to have global socio-economic connectedness and low levels of natural resource innovation-growth in impervious areas increased the annual maximum daily flow by 10%, similar to the 5-15% increase attributable to climate change. Under modest population growth, land-use decisions have little effect on storm runoff and high flows; however, for the two scenarios characterized by global socio-economic connectedness, differences in choices regarding land use and impervious area have a large impact on the potential for flooding. Results also indicate a potential interaction between climate and land use with a shift to more high flows resulting from heavy rains than from snowmelt. These results can help inform land use and development, especially when combined with assessments of effects on other ecosystem services.

Bleeding and thrombotic outcomes associated with postoperative use of direct oral anticoagulants after open peripheral artery bypass procedures.

OBJECTIVE: Widespread adoption of direct oral anticoagulants (DOACs) for atrial fibrillation and venous thromboembolism treatment has resulted in peripheral bypass patients receiving therapeutic anticoagulation with DOACs postoperatively. This study was undertaken to evaluate patient outcomes after open peripheral bypass based on anticoagulation treatment. METHODS: Postoperative treatment and outcomes of patients undergoing peripheral bypass operations between January 2012 and December 2017 from a statewide multicenter quality improvement registry were examined. Surgeons participating in the registry were surveyed on practice patterns regarding DOACs in bypass patients. Multivariate logistic regression was performed for 30-day transfusion outcomes, and multiple linear regression was performed for length of stay. RESULTS: Among 9682 patients, 7685 patients received no anticoagulation, whereas 1379 received a vitamin K antagonist (VKA) and 618 received a DOAC postoperatively. Patients receiving anticoagulation compared with no anticoagulation had a higher body mass index and were more likely to have preoperative anemia, congestive heart failure, and atrial fibrillation (all P < .001). Compared with patients receiving VKAs, patients receiving DOACs were less likely to have chronic kidney disease (P = .002) and more likely to have atrial fibrillation (P < .001). The shortest length of stay was among patients receiving no anticoagulation (median, 5 days; interquartile range, 3-9 days; P < .001), followed by DOACs (median, 6 days; interquartile range 3-11 days; P < .001) and VKAs (median, 8 days; interquartile range, 5-13 days; P < .001). Compared with patients receiving VKAs postoperatively, there was no difference in readmission for anticoagulation complications, bypass thrombectomy or thrombolysis, major amputation, or graft patency at 1 year among patients receiving DOACs. On multivariate logistic regression, patients receiving a DOAC (odds ratio, 0.743; confidence interval, 0.59-0.94; P = .011) or no anticoagulation (odds ratio, 0.792; confidence interval, 0.69-0.91; P = .001) were less likely to require transfusion within 30 days than patients taking VKAs. Approximately 70% of the surveyed surgeons reported that they "sometimes" or "always" use DOACs instead of VKAs for protection of a high-risk bypass. CONCLUSIONS: Among patients undergoing lower extremity surgical bypass, those receiving a DOAC postoperatively had a shorter length of stay and were less likely to receive a transfusion in 30 days without compromising graft patency and readmission for anticoagulation complications, thrombectomy, or thrombolysis or affecting amputation rate compared with those receiving a VKA. A majority of surgeons within the quality collaborative have adopted the use of DOACs after peripheral bypass, suggesting the need for a prospective trial evaluating DOAC safety and efficacy in patients requiring anticoagulation for high-risk bypass grafts.

The impact of sleeve gastrectomy on renal function in patients with chronic kidney disease varies with severity of renal insufficiency.

BACKGROUND: Although laparoscopic sleeve gastrectomy is known, in general, to improve renal function in patients with obesity and chronic kidney disease (CKD), its effect on estimated glomerular filtration rate (eGFR) stratified by the stage of CKD is less clear. OBJECTIVES: We aimed to evaluate the impact of sleeve gastrectomy on renal function in a stratified cohort of patients with CKD. SETTING: University Hospital. METHODS: We performed a retrospective review of 1932 patients who met National Institutes of Health's guidelines for metabolic surgery and underwent laparoscopic sleeve gastrectomy performed by 1 of 3 surgeons. One hundred sixty-four patients with CKD stages 1 through 4 were identified. RESULTS: Mean follow-up period was 1.57 ± 1.0 years. Mean age was 56.4 ± 9.9 years with a preoperative body mass index of 47 ± 9 kg/m2, which decreased to 38.9 ± 8.7 kg/m2 at most recent follow-up (P < .001). In the cohort of patients with diabetes, significant decreases were observed in mean glycated hemoglobin level, daily number of oral hypoglycemics, and daily long acting insulin use (P < .001 each). Of 67 patients with diabetes, 34.3% (n = 24) achieved complete remission. In patients with hypertension, average daily number of antihypertensives decreased (P < .001) and 22.3% (n = 31) of 133 patients with hypertension discontinued all antihypertensives. Patients with CKD stages 2, 3a, and 3b showed significant improvement in eGFR. Reinforcing this evidence of improvement, patients with CKD 3a and 3b were more likely to downstage disease compared with those with CKD 4 (58.1% versus 73.1% versus 22.7%, respectively) (P < .001). CONCLUSION: Renal function, as measured by eGFR, in patients with stages 1 and 4 CKD did not improve after laparoscopic sleeve gastrectomy; in contrast, eGFR in patients with CKD stages 2 and 3 significantly improved. Early surgical referral and intervention may be important in achieving the greatest improvement in eGFR and possibly delaying or reversing progression to end-stage renal disease.