Absolute treatment effects of novel antidiabetic drugs on a composite renal outcome: meta-analysis of digitalized individual patient data

BACKGROUND

Absolute treatment benefits-expressed as numbers needed to treat-of the glucose lowering and cardiovascular drugs, glucagon-like peptide-1 (GLP-1) receptor agonists and sodium-glucose transporter 2 (SGLT2) inhibitors on renal outcomes remain uncertain. With the present meta-analysis of digitalized individual patient data, we aimed to display and compare numbers needed to treat of both drugs on a composite renal outcome.

METHODS

From Kaplan-Meier plots of major cardiovascular outcome trials of GLP-1 receptor agonists and SGLT2 inhibitors vs. placebo, we digitalized individual patient time-to-event information on composite renal outcomes with WebPlotDigitizer 4.2; numbers needed to treat from individual cardiovascular outcome trials were estimated using parametric Weibull regression models and compared to original data. Random-effects meta-analysis generated meta-numbers needed to treat with 95% confidence intervals (CI).

RESULTS

Twelve cardiovascular outcome trials (three for GLP-1 receptor agonists, nine for SGLT2 inhibitors) comprising 90,865 participants were included. Eight trials were conducted in primary type 2 diabetes populations, two in a primary heart failure and two in a primary chronic kidney disease population. Mean estimated glomerular filtration rate at baseline ranged between 37.3 and 85.3 ml/min/1.73 m2. Meta-analyses estimated meta-numbers needed to treat of 85 (95% CI 60; 145) for GLP-1 receptor agonists and 104 (95% CI 81; 147) for SGLT2 inhibitors for the composite renal outcome at the overall median follow-up time of 36 months.

CONCLUSION

The present meta-analysis of digitalized individual patient data revealed moderate and similar absolute treatment benefits of GLP-1 receptor agonists and SGLT2 inhibitors compared to placebo for a composite renal outcome.

Meta-analysed numbers needed to treat of novel antidiabetic drugs for cardiovascular outcomes

AIMS

Absolute treatment effects-i.e. numbers needed to treat (NNTs)-of novel antidiabetic drugs for cardiovascular outcomes have not been comprehensively evaluated. We aimed to perform a meta-analysis of digitalized individual patient outcomes to display and compare absolute treatment effects.

METHODS AND RESULTS

Individual patient time-to-event information from Kaplan-Meier plots of cardiovascular mortality (CM) and/or hospitalization for heart failure (HHF) endpoints from cardiovascular outcome trials (CVOTs) evaluating dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, and sodium glucose transporter 2 (SGLT2) inhibitors vs. placebo were digitalized using WebPlotDigitizer 4.2 and the R code of Guyot et al.; Weibull regression models were generated, validated, and used to estimate NNT for individual trials; random-effects meta-analysis generated Meta-NNT with 95% confidence intervals. Sixteen CVOTs reported time-to-event information (14 in primary diabetes and 2 in primary heart failure populations). Thirteen studies including 96 860 patients were meta-analysed for CM: At the median follow-up of 30 months, Meta-NNTs were 178 (64 to ∞ to -223) for DPP-4 inhibitors, 261 (158 to 745) for GLP-1 receptor agonists, and 118 (68 to 435) for SGLT2 inhibitors. Ten studies including 96 128 patients were meta-analysed for HHF: At the median follow-up of 29 months, estimated Meta-NNTs were -644 (229 to ∞ to -134) for DPP-4 inhibitors, 441 (184 to ∞ to -1100) for GLP-1 receptor agonists, and 126 (91 to 208) for SGLT2 inhibitors. SGLT2 inhibitors were especially effective for HHF in primary heart failure populations [Meta-NNT 25 (19 to 39)] vs. primary diabetes populations [Meta-NNT 233 (167 to 385)] at 16 months of follow-up.

CONCLUSIONS

We found only modest treatment benefits of GLP-1 receptor agonists and SGLT2 inhibitors for CM and HHF in primary type 2 diabetes mellitus populations. In primary heart failure populations, SGLT2 inhibitor benefits were substantial and comparable in efficacy to established heart failure medication.

Absolute treatment effects for the primary outcome and all-cause mortality in the cardiovascular outcome trials in type 2 diabetes: a meta-analysis of individual patient data

Background and purpose

Treatment effects from the large cardiovascular outcome trials (CVOTs) in diabetes are almost exclusively communicated as hazard ratios, although reporting guidelines recommend to report treatment effects also on an absolute scale, e.g. as numbers needed to treat (NNT). We aimed to analyze NNT in CVOTs of novel oral antidiabetic drugs comparing dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, or sodium-glucose cotransporter-2 (SGLT2) inhibitors to placebo.

Methods and results

We extracted individual time-to-event information for the primary outcome and all-cause mortality from 19 CVOTs that compared DPP-4 inhibitors, GLP-1 receptor agonists, or SGLT2 inhibitors to placebo. We estimated Weibull models for each trial and outcome and derived monthly NNTs. NNTs were summarized across all trials and within drug-classes by random effects meta-analysis methods. Treatment effects in the CVOTs appear smaller if they are reported as NNTs: Overall, 60 (95%-CI: 40–124) patients have to be treated for 29 months (the median follow-up time across all trials) to avoid a single event of the primary outcome, and 101 (95%-CI: 69–191) patients have to be treated for 39 months to avoid a single death.

Conclusion

We found that the respective treatment effects of novel oral antidiabetic drugs look less impressive when communicated on an absolute scale, as numbers needed to treat. For a valid overall picture of the benefit of these drugs, trial authors should thus also report treatment effects on an absolute scale.

Funding Acknowledgement

Type of funding sources: None.

Absolute treatment effects of novel oral antidiabetic drugs on cardiovascular mortality and hospitalization for heart failure: a meta-analysis of digitalized individual patient outcomes

Background and purpose

Absolute treatment effects of novel oral antidiabetic drugs for cardiovascular outcomes have thus far not been comprehensively evaluated. We thus aimed to perform a meta-analysis of digitalized individual patient data.

Methods and results

Individual patient outcomes from Cardiovascular Outcome Trials (CVOTs) evaluating dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists and sodium glucose transporter 2 (SGLT2) inhibitors against placebo with time-to-event information for cardiovascular mortality (CM) and/or hospitalization for heart failure (HHF) endpoints were digitalized from Kaplan-Meier plots; Weibull regression models with random-effects meta-analysis were used to estimate numbers-needed-to-treat (NNT) and Meta-NNT with 95% confidence intervals (CI). Sixteen CVOTs reported time-to-event information (14 in primary diabetes, two in primary heart failure populations). Thirteen studies including 96,860 patients were meta-analyzed for CM: at the median follow-up of 30 months, Meta-NNTs were 178 (64 to ∞ to −223) for DPP-4 inhibitors, 261 (158 to 745) for GLP-1 receptor agonists and 118 (68 to 435) for SGLT2 inhibitors. Ten studies including 96,128 patients were meta-analyzed for HHF: at the median follow-up of 29 months, estimated Meta-NNTs were −644 (229 to ∞ to −134) for DPP-4 inhibitors, 441 (184 to ∞ to −1100) for GLP-1 receptor agonists and 126 (91 to 208) for SGLT2 inhibitors. SGLT2 inhibitors were especially effective for HHF in primary heart failure populations (Meta-NNT 25 (19 to 39)) vs. primary diabetes populations (Meta-NNT 233 (167 to 385)) at 16 months of follow-up.

Conclusion

We found modest treatment benefits of GLP-1 receptor agonists and SGLT2 inhibitors for CM and HHF in primary T2DM populations. In primary heart failure populations, however, SGLT2 inhibitor benefits were substantial and comparable to established heart failure medication.

Funding Acknowledgement

Type of funding sources: None.

Absolute treatment effects for the primary outcome and all-cause mortality in the cardiovascular outcome trials of new antidiabetic drugs: a meta-analysis of digitalized individual patient data

AIMS

Treatment effects from the large cardiovascular outcome trials (CVOTs) of new antidiabetic drugs are almost exclusively communicated as hazard ratios, although reporting guidelines recommend to report treatment effects also on an absolute scale, e.g. as numbers needed to treat (NNT). We aimed to analyse NNTs in CVOTs comparing dipeptidyl peptidase-4 (DPP-4) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, or sodium-glucose cotransporter-2 (SGLT2) inhibitors to placebo.

METHODS

We digitalized individual time-to-event information for the primary outcome and all-cause mortality from 19 CVOTs that compared DPP-4 inhibitors, GLP-1 receptor agonists, or SGLT2 inhibitors to placebo. We estimated Weibull models for each trial and outcome and derived monthly NNTs. NNTs were summarized across all trials and within drug classes by random effects meta-analysis methods.

RESULTS

Treatment effects in the CVOTs appear smaller if they are reported as NNTs: Overall, 100 (95%-CI: 60, 303) patients have to be treated for 29 months (the median follow-up time across all trials) to avoid a single event of the primary outcome, and 128 (95%-CI: 85, 265) patients have to be treated for 39 months to avoid a single death. NNT time courses are very similar for GLP-1 receptor agonists and SGLT2 inhibitors, whereas treatment effects with DPP-4 inhibitors are smaller.

CONCLUSIONS

We found that the respective treatment effects look less impressive when communicated on an absolute scale, as numbers needed to treat. For a valid overall picture of the benefit of new antidiabetic drugs, trial authors should also report treatment effects on an absolute scale.

Evaluation of X-ray fluorescence spectroscopy as a method for the rapid and direct determination of sodium in cheese

Cheese manufacturers indirectly determine Na in cheese by analysis of Cl using the Volhard method, assuming that all Cl came from NaCl. This method overestimates the actual Na content in cheeses when Na replacers (e.g., KCl) are used. A direct and rapid method for Na detection is needed. X-ray fluorescence spectroscopy (XRF), a mineral analysis technique used in the mining industry, was investigated as an alternative method of Na detection in cheese. An XRF method for the detection of Na in cheese was developed and compared with inductively coupled plasma optical emission spectroscopy (ICP-OES; the reference method for Na in cheese) and Cl analyzer. Sodium quantification was performed by multi-point calibration with cheese standards spiked with NaCl ranging from 0 to 4% Na (wt/wt). The Na concentration of each of the cheese standards (discs: 30mm×7mm) was quantified by the 3 methods. A single laboratory method validation was performed; linearity, precision, limit of detection, and limit of quantification were determined. An additional calibration graph was created using cheese standards made from natural or process cheeses manufactured with different ratios of Na:K. Both Na and K calibration curves were linear for the cheese standards. Sodium was quantified in a variety of commercial cheese samples. The Na data obtained by XRF were in agreement with those from ICP-OES and Cl analyzer for most commercial natural cheeses. The XRF method did not accurately determine Na concentration for several process cheese samples, compared with ICP-OES, likely due to the use of unknown types of Na-based emulsifying salts (ES). When a calibration curve was created for process cheese with the specific types of ES used for this cheese, Na content was successfully predicted in the samples. For natural cheeses, the limit of detection and limit of quantification for Na that can be determined with an acceptable level of repeatability, precision, and trueness was 82 and 246mg/100g of cheese, respectively. Calibration graphs should be created with standards that reflect the concentration range, ratio, and salt type present in the cheeses. This XRF method can be successfully used for the rapid and direct measurement of Na content in a wide variety of natural cheeses. Commercial process cheese manufacturers use proprietary blends of ES. We did find that the XRF technique worked for process cheese when the calibration graphs were created with the specific types of ES actually used.

Extra protein loss not caused by surgical bleeding in patients with ovarian cancer

BACKGROUND

[corrected] Clinical experience in patients with ovarian cancer has shown special difficulties in maintaining cardiovascular stability during surgery.

METHODS

To evaluate the causes for this observation, 15 patients with benign ovarian tumours (group I) and 13 patients with ovarian cancer (group II) were investigated perioperatively. Plasma volume (indocyanine green-dilution technique), haematocrit, plasma protein concentration, mean arterial pressure, heart rate, and central venous pressure were measured immediately before and after cytoreductive surgery.

RESULTS

Normal values of blood-, plasma-, and red cell volume were determined preoperatively in both groups, and in relation to body surface area there were no intergroup differences of these parameters. In group I, the significant decrease in red cell volume of 313 ml postoperatively was compensated for by an increase in plasma volume of 371 ml (median values). In contrast to group I, the decrease in red cell volume of 328 ml in group II was not related to a significant increase in plasma volume, so that blood volume postoperatively was 483 ml lower than preoperatively, although the same standardized infusion regimen as in group I was applied. Patients of group II had a significantly higher loss of intravascular protein (49 g vs 13 g in group I), which left the intravascular space by another way than by surgical bleeding. This extra protein loss is termed Intraoperative Protein Shift (IPS).

CONCLUSION

IPS could be an important quantity in perioperative fluid balance. We assume that different surgical procedures predispose to occurrence of differing amounts of IPS.

Isovolemic hemodilution alters the ratio of whole-body to large-vessel hematocrit (F-cell ratio). A prospective, randomized study comparing the volume effects of hydroxyethyl starch 200,000/0.62 and albumin

OBJECTIVE

To evaluate potential changes in the ratio of whole-body/large-vessel hematocrit (f-cell ratio) during isovolemic hemodilution and to compare the volume effects of 2 different plasma exchange solutions (hydroxyethyl starch 200,000/0.62 6% and human albumin 5%).

DESIGN

Prospective, randomized, controlled trial.

SETTING

Operating theater in a university hospital.

PATIENTS

24 gynecological patients scheduled for elective surgery.

INTERVENTIONS

Isovolemic hemodilution was performed using 2 different plasma exchange solutions. Plasma volume was determined using dye dilution technique before and after hemodilution. The volume of withdrawn blood was measured from the change in weight of the blood bags taking into account the specific gravity of blood.

RESULTS

The volume of administered plasma exchange solutions exceeded the amount of withdrawn blood by 80 +/- 47 ml (p < 0.001). Plasma volume was 3,067 +/- 327 ml before and 3,517 +/- 458 ml after hemodilution. Using red cell volumes calculated from measured plasma volumes and peripheral hematocrit, a deficit of 249 +/- 133 ml (p < 0.0001) in red cells after hemodilution appeared with the measured withdrawn red cell volumes taken into account. This finding can be explained by a change in the f-cell ratio during isovolemic hemodilution. The volume effect of the exchange solutions was 1.05 for hydroxyethyl starch and 0.95 for albumin.

CONCLUSIONS

The results demonstrate that a change in the f-cell ratio occurs during isovolemic hemodilution. The estimation of red cell volume or plasma volume changes by using either the hematocrit or plasma or red cell volume determinations together with the hematocrit may lead to erroneous results.

Isovolemic Hemodilution Alters the Ratio of Whole-Body to Large-Vessel Hematocrit (F-Cell Ratio)

<i>Objective: </i>To evaluate potential changes in the ratio of whole-body/large-vessel hematocrit (f-cell ratio) during isovolemic hemodilution and to compare the volume effects of 2 different plasma exchange solutions (hydroxyethyl starch 200,000/0.62 6% and human albumin 5%). <i>Design: </i>Prospective, randomized, controlled trial. <i>Setting: </i>Operating theater in a university hospital. <i>Patients: </i>24 gynecological patients scheduled for elective surgery. <i>Interventions: </i>Isovolemic hemodilution was performed using 2 different plasma exchange solutions. Plasma volume was determined using dye dilution technique before and after hemodilution. The volume of withdrawn blood was measured from the change in weight of the blood bags taking into account the specific gravity of blood. <i>Results: </i>The volume of administered plasma exchange solutions exceeded the amount of withdrawn blood by 80 ± 47 ml (p < 0.001). Plasma volume was 3,067 ± 327 ml before and 3,517 ± 458 ml after hemodilution. Using red cell volumes calculated from measured plasma volumes and peripheral hematocrit, a deficit of 249 ± 133 ml (p < 0.0001) in red cells after hemodilution appeared with the measured withdrawn red cell volumes taken into account. This finding can be explained by a change in the f-cell ratio during isovolemic hemodilution. The volume effect of the exchange solutions was 1.05 for hydroxyethyl starch and 0.95 for albumin. <i>Conclusions: </i>The results demonstrate that a change in the f-cell ratio occurs during isovolemic hemodilution. The estimation of red cell volume or plasma volume changes by using either the hematocrit or plasma or red cell volume determinations together with the hematocrit may lead to erroneous results.

Determination of plasma volume with indocyanine green in man

We investigated the feasibility of using indocyanine green (ICG) for plasma volume (PV) determination in man. Duplicate PV measurements were carried out in 23 healthy subjects to test repeatability. ICG (0.25 mg/kg) was injected intravenously into one arm and venous blood was withdrawn from the opposite arm. Optical density of plasma samples from minute 3 to 9 was measured in a densitometer. ICG concentration at injection time was determined by monoexponential extrapolation. The mean (SD) difference (MD) was -23 ml (183) or -0.6% (5.7%). Linear regression revealed PV2 = 0.92.PV1 + 226 (r = 0.92). The PV values corresponded well with data from other studies. In 26 surgical patients PV was determined using two methods: 1) the same as in healthy subjects and 2) using a modification of this method in whole blood (PVB). For PVB measurement blood was drawn through a cuvette-densitometer from an arterial line. Calculations were the same as in PV determination except for the use of hematocrit to achieve plasma concentrations of ICG from whole blood. In patients MD were -53 ml (144) or -1.3% (4.3) for PV and -19 ml (161) or -0.3% (5.1) for PVB. Comparing PVB and PV revealed MD = -113 ml (149) or -3.3% (4.2). The whole blood method is easier to perform and reduces blood waste to almost zero. In conclusion, ICG is a suitable tracer for PV determination.