Das gute Leben heute und morgen: Antibiotikaresistente Keime als Nachhaltigkeitsproblem in der Medizin

In einem ersten Kapitel wird am Beispiel der Entstehung von Antibiotikaresistenzen gezeigt, dass es in der Medizin spezifische Nachhaltigkeitsprobleme gibt, die letztlich zu einer Beeinträchtigung der Fähigkeit zukünftiger Patient:innen führen können, ihre Gesundheitsbedürfnisse zu befriedigen und ein gutes Leben zu leben. Nachdem in einem zweiten Kapitel auf den Nachhaltigkeitsbegriff genauer eingegangen wurde, wird im dritten Teil erläutert, dass und warum die Möglichkeit zur Befriedigung elementarer Gesundheitsbedürfnisse z. B. im Rahmen eines Capability-Ansatzes zu Recht als eine Bedingung für ein gutes Leben gilt. Das Konzept der Nachhaltigkeit der Vereinten Nationen fordert, die Ansprüche auf ein gutes Leben zukünftiger Patient:innen angemessen zu berücksichtigen. Im vierten Teil wird dargestellt, wie Nachhaltigkeitsforderungen im klinischen Kontext zu einem Nachhaltigkeits-Dilemma führen können, und geklärt, auf welche Weise mit diesem Dilemma umgegangen werden kann.

Wave-Vector Dependence of the Dynamics in Supercooled Metallic Liquids

We present a detailed investigation of the wave-vector dependence of collective atomic motion in Au_{49}Cu_{26.9}Si_{16.3}Ag_{5.5}Pd_{2.3} and Pd_{42.5}Cu_{27}Ni_{9.5}P_{21} supercooled liquids close to the glass transition temperature. Using x-ray photon correlation spectroscopy in a previously uncovered spatial range of only a few interatomic distances, we show that the microscopic structural relaxation process mimics the structure and presents a marked slowing down at the main average interparticle distance. This behavior is accompanied by dramatic changes in the shape of the intermediate scattering functions, which suggest the presence of large dynamical heterogeneities at length scales corresponding to a few particle diameters. A ballisticlike mechanism of particle motion seems to govern the structural relaxation of the two systems in the highly viscous phase, likely associated with hopping of caged particles in agreement with theoretical studies.

Amalgam Alternatives: Cost-Effectiveness and Value of Information Analysis

We aimed to assess the cost-effectiveness of amalgam alternatives—namely, incrementally placed composites (IComp), composites placed in bulk (BComp), and glass ionomer cements (GIC). In a sensitivity analysis, we also included composite inlays (CompI) and incrementally placed bulk-fills (IBComp). Moreover, the value of information (VOI) regarding the effectiveness of all strategies was determined. A mixed public-private-payer perspective in the context of Germany was adopted. Bayesian network meta-analyses were performed to yield effectiveness estimates (relative risk [RR] of failure). A 3-surfaced restoration on a permanent molar in initially 30-y-old patients was followed over patients’ lifetime using a Markov model. Restorative and endodontic complications were modeled; our outcome parameter was the years of tooth retention. Costs were derived from insurance fee items. Monte Carlo microsimulations were used to estimate cost-effectiveness, cost-effectiveness acceptability, and VOI. Initially, BComp/GIC were less costly (110.11 euros) than IComp (146.82 euros) but also more prone to failures (RRs [95% credible intervals (CrI)] were 1.6 [0.8 to 3.4] for BComp and 1.3 [0.5 to 5.6] for GIC). When following patients over their lifetime, IComp was most effective (mean [SD], 41.9 [1] years) and least costly (2,076 [135] euros), hence dominating both BComp (40.5 [1] years; 2,284 [126] euros) and GIC (41.2 years; 2,177 [126] euros) in 90% of simulations. Eliminating the uncertainty around the effectiveness of the strategies was worth 3.99 euros per restoration, translating into annual economic savings of 87.8 million euros for payers. Including CompI and IBComp into our analyses had only a minimal impact, and our findings were robust in further sensitivity analyses. In conclusion, the initial savings by BComp/GIC compared with IComp are very likely to be compensated by the higher risk of failures and costs for retreatments. CompI and IBComp do not seem cost-effective. All alternatives are likely to be inferior to amalgam. The VOI was considerable, and future studies may yield significant economic benefits.

In-Office Application of Fluoride Gel or Varnish: Cost-Effectiveness and Expected Value of Perfect Information Analysis

Application of fluoride gel/varnish (FG/FV) reduces caries increments but generates costs. Avoiding restorative treatments by preventing caries might compensate for these costs. We assessed the cost-effectiveness of dentists applying FG/FV in office and the expected value of perfect information (EVPI). EVPI analyses estimate the economic value of having perfect knowledge, assisting research resource allocation. A mixed public-private-payer perspective in Germany was adopted. A population of 12-year-olds was followed over their lifetime, with caries increments modelled using wide intervals to reflect the uncertainty of caries risk. Biannual application of FV/FG until age 18 years was compared to no fluoride application. Effectiveness parameters and their uncertainty were derived from systematic reviews. The health outcome was caries increment (decayed, missing, or filled teeth; DMFT). Cost calculations were based on fee catalogs or microcosting, including costs for individual-prophylactic fluoridation and, for FG, an individualized tray, plus material costs. Microsimulations, sensitivity, and EVPI analyses were performed. On average and applied to a largely low-risk population, no application of fluoride was least costly but also least effective (EUR 230; 11 DMFT). FV was more costly and effective (EUR 357; 7 DMFT). FG was less effective than FV and also more costly when using individualized trays. FV was the best choice for payers willing to invest EUR 39 or more per avoided DMFT. This cost-effectiveness will differ in different settings/countries or if FG/FV is applied by other care professionals. The EVPI was mainly driven by the individual's caries risk, as FV/FG were significantly more cost-effective in high-risk populations than in low-risk ones. Future studies should focus on caries risk prediction.

Cost-effectiveness of Different Post-retained Restorations

OBJECTIVES

Dentists can choose between metal and fiber post systems to provide post-retained restorations. The risk of tooth loss and other complications differs between different post systems, as do the initial treatment costs. We aimed to assess the cost-effectiveness of (1) cast metal (MC), (2) preformed metal (MP), (3) glass fiber (GF), and (4) carbon fiber (CF) post-retained restorations.

METHODS

A mixed public-private payer's perspective within German healthcare was taken. Risks of complications were extracted from systematic reviews. Costs were estimated by using fee items and 2016 material costs. A Markov model was constructed to follow up an endodontically treated molar receiving a post-retained crown in an initially 50-year-old patient during his lifetime. Monte Carlo microsimulations were performed to assess lifetime costs and tooth retention time.

RESULTS

MPs were least costly (€692€), retaining teeth for 26.7 years. GFs were more costly (€745€), retaining teeth for 27.6 years. MCs were minimally more effective but also more costly than GFs (€774€). CFs were less effective and most expensive (€825€, 26.7 years). For payers willing to invest more than €60€ per tooth retention year, GF was cost-effective. Payers willing to invest an additional €670€ found MC to be cost-effective. These findings were found robust in sensitivity analyses.

CONCLUSIONS

For payers not willing to invest additional money for longer tooth retention, MP seemed most suitable to retain restorations. For payers with additional willingness to pay, GF seemed suitable, retaining teeth for longer. MC was only cost-effective under very high willingness to pay. CF is not recommendable on the basis of their cost-effectiveness.

Taxing sugar-sweetened beverages: impact on overweight and obesity in Germany

BACKGROUND

Consumption of sugar-sweetened beverages (SSBs) increases the risk of overweight and obesity. Taxing SSBs could decrease daily energy consumption and body weight. This model-based study evaluated the impact of a 20% SSB-sales tax on overweight and obesity in the context of Germany.

METHODS

The population aged 15-79 years was modelled. Taxation was assumed to affect energy consumption via demand elasticities, which affected weight and BMI. Model-based analysis was performed to estimate the tax impact on BMI in different age, gender and income groups.

RESULTS

Implementing a 20% SSB tax reduced energy consumption mainly in younger age groups, males, and those with low income. Taxation decreased the mean BMI in younger groups, with the largest decrease in those aged 20-29 years, while effects in groups 60 years or above were minimal. In absolute terms, taxation was estimated to avoid 1,028,000 (-3% relative reduction) overweight individuals and 479,000 obese individuals (-4%). Overweight decreased the most in males aged 20-29 years (408,000 fewer cases /-22%), the same applied for obesity (204,000/-22%).

CONCLUSIONS

An SSB tax could have significant impact on overweight and obesity, which could translate into substantial reductions of morbidity and mortality.

Effects of Taxing Sugar-Sweetened Beverages on Caries and Treatment Costs

Caries increment is affected by sugar-sweetened beverage (SSB) consumption. Taxing SSBs could reduce sugar consumption and caries increment. The authors aimed to estimate the impact of a 20% SSB sales tax on caries increment and associated treatment costs (as well as the resulting tax revenue) in the context of Germany. A model-based approach was taken, estimating the effects for the German population aged 14 to 79 y over a 10-y period. Taxation was assumed to affect beverage-associated sugar consumption via empirical demand elasticities. Altered consumption affected caries increments and treatment costs, with cost estimates being calculated under the perspective of the statutory health insurance. National representative consumption and price data were used to estimate tax revenue. Microsimulations were performed to estimate health outcomes, costs, and revenue impact in different age, sex, and income groups. Implementing a 20% SSB sales tax reduced sugar consumption in nearly all male groups but in fewer female groups. The reduction was larger among younger than older individuals and among those with low income. Taxation reduced caries increment and treatment costs especially in younger (rather than older) individuals and those with low income. Over 10 y, mean (SD) net caries increments at the population level were 82.27 (1.15) million and 83.02 (1.08) million teeth at 20% and 0% SSB tax, respectively. These generated treatment costs of 2.64 (0.39) billion and 2.72 (0.35) billion euro, respectively. Additional tax revenue was 37.99 (3.41) billion euro over the 10 y. In conclusion and within the limitations of this study's perspective, database, and underlying assumptions, implementing a 20% sales tax on SSBs is likely to reduce caries increment, especially in young low-income males, thereby also reducing inequalities in the distribution of caries experience. Taxation would also reduce treatment costs. However, these reductions might be limited in the total population.

Retention costs of periodontally compromised molars in a German population

AIM

This study assessed the long-term costs per retention year for periodontally affected molars.

METHODS

A cohort of 379 compliant subjects was retrospectively evaluated. Periodontal, restorative, endodontic, prosthetic and surgical treatment costs were estimated based on fee items of the private German health insurance. Costs/year were calculated and the impact of tooth- and subject-related factors on this cost-effectiveness ratio assessed using generalized linear-mixed modelling.

RESULTS

2306 molars received non-regenerative initial and supportive therapy and were followed until extraction or censoring (in mean (SD): 16.5 [6.8] years). Per year, 0.07 (SD: 0.12) deep scalings, 0.04 (0.11) open flap debridements, 0.01 (0.04) resective therapies and 2.49 (0.12) SPTs had been provided. Few teeth received non-periodontal treatments. Costs/year decreased significantly with each tooth a patient had at baseline (mean difference: -0.01, 95% CI: -0.02/-0.01 Euro/year), and increased with each mm of probing-pocket depth (0.04 [0.03/0.06] Euro/year), in upper (0.07 [0.11/0.31] Euro/year) or mobile molars (up to 0.33 [0.18/0.48] Euro/year), those with bone loss (up to 0.11 [0.04/0.17] Euro/year), endodontic treatment (0.24 [0.15/0.33] Euro/year), peri-apical lesions (0.24 [0.11/0.38]) and prosthetic treatment (0.54 [0.49/0.59] Euro/year).

CONCLUSIONS

Annual costs for retaining periodontally affected molars were limited, and associated mainly with tooth-level factors.

Detecting Proximal Secondary Caries Lesions

When choosing detection methods for secondary caries lesions, dentists need to weigh sensitivity, allowing early initiation of retreatments to avoid lesion progression, against specificity, aiming to reduce risks of false-positive diagnoses and invasive overtreatments. We assessed the cost-effectiveness of different detection methods for proximal secondary lesions using Monte Carlo microsimulations. A vital permanent molar with an occlusal-proximal restoration was simulated over the lifetime of an initially 20-y-old. Three methods were compared: biannual tactile detection, radiographic detection every 2 y, and biannual laser fluorescence detection. Methods were employed either on their own or in pairwise combinations at sensitive and specific thresholds estimated with systematically collected data. A mixed public-private payer perspective in the context of German health care was applied. Effectiveness was calculated as years of tooth retention. Net-benefit analyses were used to evaluate cost-effectiveness acceptability at different willingness-to-pay thresholds. Radiographic detection verified by tactile assessment (both at specific thresholds) was least costly (mean, 1,060 euros) but had limited effectiveness (mean retention time, 50 y). The most effective but also more costly combination was laser fluorescence detection verified by radiography, again at specific thresholds (1157 euros, 53 y, acceptable if willingness to pay >32 euro/y). In the majority of simulations, not combining detection methods or applying them at sensitive thresholds was less effective and more costly. Net benefits were not greatly altered by applying different discounting rates or using different baseline prevalence of secondary lesions. Current detection methods for secondary lesions should best be used in combination, not on their own, at specific thresholds to avoid false-positive diagnoses leading to costly and invasive overtreatment. The relevant characteristics, such as predictive value, of different methods should be assessed in longitudinal clinical studies.

Preventing and Treating Peri-Implantitis: A Cost-Effectiveness Analysis

BACKGROUND

A large number of treatments for peri-implantitis are available, but their cost-effectiveness remains uncertain. This study evaluates the cost-effectiveness of preventing and treating peri-implantitis.

METHODS

A Markov model was constructed that followed each implant over 20 years. Supportive implant therapy (SIT) for managing peri-implant mucositis and preventing development of peri-implantitis was either provided or not. Risk of peri-implantitis was assumed to be affected by SIT and the patient's risk profile. If peri-implantitis occurred, 11 treatment strategies (non-surgical or surgical debridement alone or combined with adjunct therapies) were compared. Treatments and risk profiles determined disease progression. Modeling was performed based on systematically collected data. Primary outcomes were costs and proportion of lost implants, as assessed via Monte Carlo microsimulations.

RESULTS

Not providing SIT and performing only non-surgical debridement was both least costly and least effective. The next best (more costly and effective) option was to provide SIT and perform surgical debridement (additional 0.89 euros per 1% fewer implants lost). The most effective option included bone grafts, membranes, and laser treatment (56 euros per 1%). For patients at high risk, the cost-effectiveness of SIT increased, whereas in low-risk groups, a cost-optimized strategy was cost-effective.

CONCLUSIONS

Although clinical decision-making will be guided mainly by clinical condition, cost-effectiveness analyses might add another perspective. Based on these findings, an unambiguous comparative effectiveness ranking was not established. However, cost-effectiveness was predominantly determined by provision of SIT and initial treatment costs. Transferability of these findings to other healthcare systems needs further confirmation.

Detection and treatment of proximal caries lesions: Milieu-specific cost-effectiveness analysis

OBJECTIVES

Dental caries lesions are highly prevalent, concentrated in high-risk groups, and often affect proximal tooth surfaces. Choosing a caries detection method determines the available treatment options: radiographically detected early lesion stages might receive non-, micro-, or invasive treatments, whilst visually tactile detected lesions are often advanced and mostly require invasive treatment. Thus, the choice of detection method impacts on patients via the applied treatment. We compared the cost-effectiveness of combinations of detections and treatments of proximal lesions in different populations which did or did not receive prevention during adolescence. These cost-effectiveness comparisons of different detection-treatment combinations should aid clinical decision making and improve resource allocation.

METHODS

A Markov-model was constructed to follow a proximal posterior surface in a 12-year-old German over his lifetime. Prevalence, validity and transition probabilities were extracted from the literature. Microsimulations were performed to evaluate costs (Euro) per tooth-retention-time (years).

RESULTS

For populations with low risk, radiographic detection plus non-invasive treatment without (270 Euro, 61.5 years) and with prevention (312 Euro, 63.0 years), as well as radiographic detection plus micro-invasive treatment and prevention (373 Euro, 64.0 years) were cost-effective. For populations with high risk, radiographic detection plus micro-invasive treatment without (427 Euro, 58.5 years) and with prevention (436 Euro, 61.0 years) were cost-effective. Combinations involving invasive treatments had limited cost-effectiveness.

CONCLUSIONS

Caries detection methods should be evaluated regarding the cost-effectiveness resulting from their use in different populations.

CLINICAL SIGNIFICANCE

Caries detection methods are usually evaluated regarding their validity compared to a gold standard. We demonstrate that the cost-effectiveness stemming from using different detection methods additionally depends on the treatment options determined by different methods, and the examined population. Dentists' choice of a detection method should not only be guided by its validity, but also by its specific benefits in different populations.

Cost-effectiveness of caries excavations in different risk groups - a micro-simulation study

BACKGROUND

Whilst being the most prevalent disease worldwide, dental caries is increasingly concentrated in high-risk populations. New caries treatments should therefore be evaluated not only in terms of their cost-effectiveness in individuals, but also their effects on the distribution of costs and benefits across different populations. To treat deep caries, there are currently three strategies: selective (one-step incomplete), stepwise (two-step incomplete) and complete excavation. Building on prior research that found selective excavation generally cost-effective, we compared the costs-effectiveness of different excavations in low- and high-risk patients, hypothesizing that selective excavation had greater cost-effectiveness-advantages in patients with high compared with low risk.

METHODS

An average tooth-level Markov-model was constructed following the posterior teeth in an initially 18-year old male individual, either with low or high risk, over his lifetime. Risk was assumed to be predicted by several parameters (oral hygiene, social position, dental service utilization), with evidence-based transition probabilities or hazard functions being adjusted for different risk status where applicable. Total lifetime treatment costs were estimated for German healthcare, with both mixed public-private and only private out-of-pocket costs being calculated. For cost-effectiveness-analysis, micro-simulations were performed and joint parameter uncertainty introduced by random sampling of probabilities. Cohort analyses were used for assessing the underlying reasons for potential differences between strategies and populations.

RESULTS

Selective excavation was more effective and less costly than both alternatives regardless of an individual's risk. All three strategies were less effective and more costly in patients with high compared with low risk, whilst the differences between risk groups were smallest for selective excavation. Thus, the cost-effectiveness-advantages of selective excavation were more pronounced in high-risk groups, who also benefitted the most from reduced private out-of-pocket treatment costs.

CONCLUSIONS

Whilst caries excavation does not tackle the underlying sources for both the development of caries lesions and the potential differences of individuals' risk status, selective excavation seems most suitable to treat deep lesions, especially in patients with high risk, who over-proportionally benefit from the resulting health-gains and cost-savings.

Detecting and treating occlusal caries lesions: a cost-effectiveness analysis

The health gains and costs resulting from using different caries detection strategies might not only depend on the accuracy of the used method but also the treatment emanating from its use in different populations. We compared combinations of visual-tactile, radiographic, or laser-fluorescence-based detection methods with 1 of 3 treatments (non-, micro-, and invasive treatment) initiated at different cutoffs (treating all or only dentinal lesions) in populations with low or high caries prevalence. A Markov model was constructed to follow an occlusal surface in a permanent molar in an initially 12-y-old male German patient over his lifetime. Prevalence data and transition probabilities were extracted from the literature, while validity parameters of different methods were synthesized or obtained from systematic reviews. Microsimulations were performed to analyze the model, assuming a German health care setting and a mixed public-private payer perspective. Radiographic and fluorescence-based methods led to more overtreatments, especially in populations with low prevalence. For the latter, combining visual-tactile or radiographic detection with microinvasive treatment retained teeth longest (mean 66 y) at lowest costs (329 and 332 Euro, respectively), while combining radiographic or fluorescence-based detections with invasive treatment was the least cost-effective (<60 y, >700 Euro). In populations with high prevalence, combining radiographic detection with microinvasive treatment was most cost-effective (63 y, 528 Euro), while sensitive detection methods combined with invasive treatments were again the least cost-effective (<59 y, >690 Euro). The suitability of detection methods differed significantly between populations, and the cost-effectiveness was greatly influenced by the treatment initiated after lesion detection. The accuracy of a detection method relative to a "gold standard" did not automatically convey into better health or reduced costs. Detection methods should be evaluated not only against their criterion validity but also the long-term effects resulting from their use in different populations.

Costs and effectiveness of treatment alternatives for proximal caries lesions

Objectives

Invasive therapy of proximal caries lesions initiates a cascade of re-treatment cycles with increasing loss of dental hard tissue. Non- and micro-invasive treatment aim at delaying this cascade and may thus reduce both the health and economic burden of such lesions. This study compared the costs and effectiveness of alternative treatments of proximal caries lesions.

Methods

A Markov-process model was used to simulate the events following the treatment of a proximal posterior lesion (E2/D1) in a 20-year-old patient in Germany. We compared three interventions (non-invasive; micro-invasive using resin infiltration; invasive using composite restoration). We calculated the risk of complications of initial and possible follow-up treatments and modelled time-dependent non-linear transition probabilities. Costs were calculated based on item-fee catalogues in Germany. Monte-Carlo-microsimulations were performed to compare cost-effectiveness of non- versus micro-invasive treatment and to analyse lifetime costs of all three treatments.

Results

Micro-invasive treatment was both more costly and more effective than non-invasive therapy, with ceiling-value-thresholds for willingness-to-pay between 16.73 € for E2 and 1.57 € for D1 lesions. Invasive treatment was the most costly strategy. Calculated costs and effectiveness were sensitive to lesion stage, patient’s age, discounting rate and assumed initial treatment costs.

Conclusions

Non- and micro-invasive treatments have lower long-term costs than invasive therapy of proximal lesions. Micro-invasive therapy had the highest cost-effectiveness for treating D1 lesions in young patients. Decision makers with a willingness-to-pay over 16.73 € and 1.57 € for E2 and D1 lesions, respectively, will find micro-invasive treatment more cost-effective than non-invasive therapy.

Cost-effectiveness of One- and Two-step Incomplete and Complete Excavations

The treatment of deep caries lesions carries significant risks for the integrity of the pulp and often initiates a cascade of re-interventions. Incomplete caries removal may reduce these risks and avoid or delay re-treatment. The present study analyzed the cost-effectiveness of one- and two-step incomplete as well as complete excavations. We used Markov models to simulate treatment of a molar tooth with a deep caries lesion in a 15-year-old patient. Retention of the tooth and its vitality as effectiveness measures as well as accruing costs were analyzed over the patient’s lifetime. The model adopted a public-private-payer perspective within German health care. Transition probabilities were calculated based on literature reviews. Monte-Carlo microsimulations were performed with 6-month cycles. One-step incomplete excavation resulted in lower long-term costs and in longer-retained teeth and their vitality (means: 53.5 and 41.0 yrs) compared with two-step incomplete (52.5 and 37.5 yrs) and complete excavations (49.5 and 31.0 yrs), and dominated the other strategies in 70% to 100% of simulations. Regardless of the assumed willingness-to-pay ceiling value, one-step incomplete excavation had the highest probability of being cost-effective. Despite limited evidence levels of input data, we expect one-step incomplete excavation to reduce costs while retaining deeply carious teeth and their vitality for longer.

Transitivity in health utility measurement: An experimental analysis

Several experimental studies have observed substantial violations of transitivity for decisions between risky lotteries over monetary outcomes. The goal of our experiment is to test whether these violations also affect the evaluation of health states. A particular feature of our experimental design is that it takes into account the possible role of decision errors for generating violations of transitivity. Since we find neither substantial nor systematic deviations from transitive choice behaviour, we can conclude that previously reported violations do not seem to bias health utility measurement.

The impact of new drug launches on the loss of labor from disease and injury: evidence from German panel data

We study the impact of new drug launches on early retirement due to disease and injury in the German labor force between 1988 and 2004. We show that new drug launches have substantially helped to reduce the loss of labor at the disease-level over time. In Western Germany alone, each new chemical entity is estimated to have saved on average around 200 working years in every year of the observation period. Controlling for individual determinants of retirement, the 2001 reform of pension laws appears to have led to further reductions in the loss of labor from disease and injury.

The welfare costs of HIV/AIDS in eastern Europe: an empirical assessment using the economic value-of-life approach

Based on the aggregation of individual willingness-to-pay for a statistical life, we calibrate an inter-temporal optimisation model to determine the aggregate welfare loss from HIV/AIDS in 25 Eastern European countries. Assuming a discount rate of 3%, we find a total welfare loss for the whole region that exceeds US $800 billion, approximately 10% of the region's annual GDP between 1995 and 2001. Although prevalence and incidence rates diverge sharply between countries-with central Europe far less affected than major countries in the Commonwealth of Independent States and the Baltics-the epidemic is likely to spread to all countries unless a coherent strategy of prevention and treatment is backed up by substantial increases in healthcare investments. The sheer size of this task and the international nature of the epidemic render this one of the most important current challenges for all of Europe.

In vitro effects of amylin on carbohydrate metabolism in liver cells

Amylin, a peptide found in pancreatic amyloid deposits, may be involved in NIDDM. The effects of biosynthetic human amylin on multiple aspects of carbohydrate metabolism were studied in freshly isolated and cultured liver cells (rat hepatocytes and HepG2 cells). Acute exposure of culture liver cells to amylin had no effect on glucose incorporation into glycogen. Amylin directly reduced glucose oxidation through the hexose monophosphate shunt. The glycolytic pathway was unaffected. Amylin stimulated both glycogenolysis and gluconeogenesis. These effects were largest at amylin concentrations of 1-10 pM. Insulin partially inhibited both of these responses. Glucagon stimulated glycogenolysis and gluconeogenesis to a similar extent as amylin but required concentrations 100- to 500-fold as high. Thus, amylin, at physiologic concentrations, can impair some aspects of glucose use in liver cells and is also capable of directly stimulating glucose production, suggesting a possible involvement of amylin in the impaired glucose disposal and elevated hepatic glucose output of NIDDM.