Nutritional Status in Adults With Diabetic Foot Ulcers (NutriDFU-P)

Nutritional Status in Adults With Diabetic Foot in an Outpatient Wound Clinic: A Feasibility and Pilot Study

This feasibility and pilot study has two aims. The primary aim is to assess the feasibility of collecting clinical, nutritional, and functional data among adults with diabetic foot ulcers (DFUs) who are treated at an outpatient wound clinic. Specifically, the study will evaluate recruitment and inclusion rates, the relevance and clinical utility of selected variables, and assess the completeness and reliability of data collection.

The secondary aim is to provide a preliminary characterisation of nutritional status, dietary intake, body composition, muscle strength, mobility, and wound-related quality of life, to inform the design and methodology of a future full-scale national study.

DFUs are associated with delayed healing, recurrent infections, reduced quality of life, and increased risk of hospitalization and amputation. These conditions are frequently accompanied by systemic inflammation, impaired circulation, and metabolic disturbances, which may increase nutritional requirements and negatively affect wound healing.

Despite nutrition being recognized as a modifiable factor of ulcer healing, the nutritional status of individuals with DFUs remains insufficiently characterised, and evidence regarding clinically relevant nutritional deficiencies in this population is limited.

Participants will undergo assessment of height, weight, body composition, handgrip strength, and a 24-hour dietary recall interview during an outpatient clinic visit. Nutritional screening questionnaires and patient-reported measures of appetite, nutritional impact symptoms, mobility, and quality of life will be collected through telephone interviews within one week of the clinical visit.

Eligible participants are adults (>18 years) who are referred to the outpatient wound clinic with a hard-to-heal foot ulcer. Participants must be able to communicate in Danish or English.

Study Overview

• Status: Not yet recruiting
• Conditions: Wound Healing; Nutrition Assessment; Ulcer Foot; Malnutrition (Calorie); Bio-Impedance Measurements; Dietary Intake Assessment; Diabetic Foot Ulcers (DFU)
• Intervention / Treatment: Behavioral: Protein supplementation and nutrition education

Detailed Description

Background Diabetic Foot Ulcers (DFUs) affect up to one third of individuals with diabetes and are associated with systemic inflammation, impaired circulation, and metabolic disturbances that may increase nutritional requirements and may impair collagen synthesis, immune function, and tissue repair in the foot ulcer. Despite nutrition being recognized as a modifiable factor in the ulcer healing process, the nutritional status of individuals with DFUs remains insufficiently characterized, and evidence regarding clinically relevant nutritional deficiencies in this population is limited. This feasibility and pilot study is designed to test the data collection procedure and generate preliminary descriptive data on nutritional status in a Danish outpatient population, in preparation for a future full-scale multicentre study.

Study Setting and Design Prospective observational feasibility and pilot study conducted at the Wound Outpatient Clinic, Department of Orthopaedic Surgery, Hvidovre Hospital, Denmark. Data are collected at two time points: a scheduled outpatient visit (Baseline) and a telephone interview within one week.

Recruitment Eligible patients are identified through the scheduled appointment list on designated inclusion days (Monday and Wednesdays). Wound care nurses review referrals in the electronic health record system prior to each clinic day and identify potentially eligible patients in collaboration with the research team. Upon arrival, patients are informed about the opportunity to participate in a research study and if patients express interest the researcher will provide oral and written information. Written informed consent is obtained prior to any data collection.

Data collected during the outpatient visit - Baseline:

• Anthropometry: (height, weight, BMI). If the participant is unable to stand upright, height is estimated from knee-to-heel length or fingertip-to-sternum distance (estimated 5 minutes)
• Body composition: bioelectrical impedance analysis (BIA) using the InBody S10, measuring muscle mass, fat percentage, and fluid balance. Performed between wound dressing removal and re-application. Omitted in participants with implanted electronic devices; mid-upper arm muscle circumference (MAMC) used as surrogate where BIA is not feasible (estimated 10 minutes)
• Muscle strength: Handgrip dynamometry, three maximal attempts with dominant hand, highest value recorded (estimated 10 minutes)
• Dietary intake: 24-hour dietary recall interview assessing all foods and beverages consumed in the preceding 24 hours. Portion sizes estimated using standardised photographic aids (Technical University of Denmark (DTU): National Dietary Survey) (estimated duration: 40 minutes). Macro- and micronutrient intake are calculated using www.Vitakost.dk

Data collected during telephone follow-up (Within One Week)

• Malnutrition is diagnosed according to the Global Leadership Initiative on Malnutrition (GLIM), requiring at least one phenotypic criterion (low muscle mass by BIA or MAMC, low BMI, or unintentional weight loss) and one etiologic criterion. In this pilot study, the etiologic criterion will be based solely on reduced food intake or assimilation, assessed by 24-hour dietary recall and the presence of nutritional impact symptoms (NIS). Inflammatory markers are not available as routine clinical data in this outpatient setting and will not be included in GLIM classification. The availability and accessibility of routine biochemical data will be assessed as part of the feasibility evaluation to inform data collection procedures for the future full-scale study.
• NIS factors: The Patient-Generated Subjective Global Assessment Short Form (PG-SGA SF, Box 3) will be used to identify symptoms impairing food intake, including nausea, vomiting, diarrhoea, constipation, mouth sores, dry mouth, pain, taste changes, and reduced appetite. NIS data will contribute to the etiologic criterion of reduced food intake or assimilation within the GLIM malnutrition assessment
• Physical activity and mobility: (Life-Space Assessment- Denmark, LSA-DK) assessing mobility range inside and outside the home over the preceding four weeks
• Wound-related quality of life: Wound-QoL questionnaire, covering physical, psychological, and everyday life domains. Scored according to the Wound-QoL scoring manual; higher scores indicate greater impairment
• Demographic data: age, sex, ethnic background, marital status, living situation, educational level, work status, and need for community care or nursing.
• Clinical data include comorbidity burden assessed using the Charlson Comorbidity Index, diabetes type and duration, latest glycated haemoglobin (HbA1c) value, smoking status, foot deformities, previous foot ulceration, number of active ulcers, previous ulcer healing and recurrence, antibiotic treatment related to the foot ulcer, and symptoms of infections (fever).

Data management All data are recorded in REDCap, supported by the Centre for IT, Medico and Telematic Services (CIMT), Capital Region of Denmark, in accordance with approval from the Danish Data Protection Agency.

Statistical analysis Feasibility outcomes will be reported as proportions with 95% confidence intervals, evaluated against an a priori success threshold of ≥70% protocol completion. Continuous variables will be summarised as means ± Standard Deviation (SD) or medians with Interquartile Range (IQR). Nutritional status will be classified according to the GLIM criteria. Associations between nutritional variables are exploratory and hypothesis-generating.

Sample Size A formal sample size calculation is not applicable. A sample of 30 participants is sufficient to assess recruitment feasibility and generate preliminary descriptive data, consistent with recommendations for pilot studies

• Study Type: Observational
• Enrollment (Estimated): 30

Contacts and Locations

• Study Contact: Name: Pia S Jensen, PhD; Phone Number: +45 38622464; Email: Ann.Pia.Soee.Lytken.Jensen@regionh.dk
• Study Contact Backup: Name: Julie W Egholm, MD; Email: julie.weber.egholm.01@regionh.dk

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

Adult patients with non-healing diabetic foot ulcers (DFUs) receiving treatment at the outpatient clinic at Hvidovre Hospital.

Description

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosed with diabetes type 1 or type 2
• Presence of one or more DFUs
• Receiving treatment in a participating outpatient wound clinic
• Able to provide written informed consent

Exclusion Criteria:

• Above ankle amputation of the contralateral leg
• Current treatment with intravenous antibiotics for acute infection.
• Current hospitalisation for acute surgical management of the foot ulcer
• Declining or unable to participate in a telephone follow-up interview.
• Current long-term enteral (tube feeding) or parenteral nutritional support.

Exclusion criteria for bioelectrical impedance analysis (BIA)

- Presence of a cardiac pacemaker or other implanted electronic device

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Single cohort: Adults with type 1 or type 2 diabetes and one or more active DFUs; The cohort receive treatment at the Wound Outpatient Clinic, Hvidovre Hospital. No intervention is administered as part of this study.	Behavioral: Protein supplementation and nutrition education; The intervention consists of nutrition education and oral protein supplementation. Participants receive an information leaflet and brief guidance on protein intake for wound healing, along with an offer of a protein drink during outpatient visits.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Feasibility of the data collection protocol	The primary outcome is the proportion of enrolled participants who complete all components of the data collection protocol, defined as: (1) completion of all anthropometric and functional assessments during the outpatient clinic visit, and (2) completion of the telephone interview within one week of the clinic visit. Both components must be completed for a participant to be counted as a completer. Results reported as a single proportion (%). A priori success threshold: ≥70% of enrolled participants complete all data collection components. If 40-69 % complete the data collection modifications are needed and if less that 40 % completion the study is not feasible in its current form. Unit of Measure: Percentage of eligible patients (%)	From inclusion to completion of telephone interview, approximately 1 week

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Recruitment rate	Proportion of eligible patients who consent to participate, calculated as the number of enrolled participants divided by the number of eligible patients identified during the inclusion period. Reasons for non-participation will be recorded and used descriptively to contextualize the recruitment rate. Results reported as a single percentage (%). Feasibility thresholds: Feasible as is: ≥60% of eligible patients consent to participate; Feasible with modifications: 40-59% consent - barriers identified and addressable; Not feasible: <40% consent - eligibility criteria or recruitment procedure require revision Unit of Measure: Percentage of eligible patients (%)	Duration of inclusion period, approximately 3 months
Completeness of individual variables	Proportion of missing data assessed per variable across all enrolled participants. Additional variables from InBody S10 including skeletal muscle mass (kg) and ECW/TBW ratio will be assessed descriptively to evaluate data completeness and measurement feasibility for inclusion in the future full-scale study. Feasibility thresholds: Feasible as is: ≥80% data completeness per variable; Feasible with modifications: 60-79% completeness - protocol or instrument adjustment indicated; Not feasible: <60% completeness - variable should be reconsidered for the future full-scale study Unit of Measure: Proportion of complete data per variable (%)	From inclusion to completion of telephone interview, approximately one week
Duration of clinic visit assessments	Time required to complete all clinic visit assessments (anthropometry, bioelectrical impedance analysis (BIA) / mid-upper arm muscle circumference (MAMC), handgrip strength, 24-hour dietary recall interview, recorded in minutes. Results reported as mean ± SD. Feasibility thresholds: Feasible as is: Clinic visit assessments completable within 80 minutes; ≥75% of participants complete the telephone interview within 1 week; Feasible with modifications: 81-120 minutes OR 60-74% telephone completion - procedural adjustments indicated; Not feasible: >120 minutes OR <60% telephone completion - protocol requires substantial redesign Unit of Measure: Minutes	Measured at baseline clinical visit and telephone interview within one week
Telephone interview completion rate	Proportion of enrolled participants who complete the telephone interview within one week of the clinic visit. Results reported as percentage (%). Feasibility thresholds: Feasible as is: ≥75%; Feasible with modifications: 60-74% - procedural adjustments indicated; Not feasible: <60% - protocol requires substantial redesign Unit of Measure: Percentage of participants (%)	Measured at baseline and telephone interview within one week
Participant acceptance and compliance	Participant acceptance of and compliance with data collection procedures assessed descriptively, including proportion of participants who complete each assessment without refusal or withdrawal. Results reported as number and proportion (n, %) per assessment. Unit of Measure: Number and proportion of participants (n, %)	Measured at baseline clinic visit
Prevalence of malnutrition risk	Proportion of participants meeting Global Leadership Initiative on Malnutrition (GLIM) criteria for malnutrition, requiring at least one phenotypic criterion (low muscle mass by bioelectrical impedance analysis (BIA) / mid-upper arm muscle circumference (MAMC), low BMI, or unintentional weight loss) and one etiologic criterion (reduced food intake assessed by 24-hour dietary recall interview and Nutritional Impact Symptoms (NIS)). Results reported as a single proportion (%). Unit of Measure: Proportion of participants meeting GLIM criteria (n, %)	Measured at baseline clinic visit
Fat-free mass index	Fat-free mass index (kg/m²) and fat mass percentage assessed by BIA. Results reported as mean ± standard deviation (SD) and compared to age- and sex-adjusted reference values. Unit of Measure: kg/m²	Measured at baseline clinic visit
Fat mass percentage	Fat mass percentage assessed by bioelectrical impedance analysis (BIA). Results reported as mean ± SD and compared to age- and sex-adjusted reference values. Unit of Measure: Percentage (%)	Measured at baseline clinic visit
Mean daily energy intake	Mean daily energy intake assessed by 24-hour dietary recall. Adequacy evaluated against Nordic Nutrition Recommendations 2023. Results reported as mean ± SD. Data will be used to describe nutritional status in this patient population and to inform the design of the future full-scale study. Selected micronutrient intakes (vitamin C, vitamin D, zinc) will additionally be assessed and reported descriptively as part of the overall dietary analysis. Unit of Measure: kcal/day	Measured at baseline clinic visit
Wound-related quality of life	Wound-related quality of life assessed by the validated Wound-QoL questionnaire, scored according to the Wound-QoL scoring manual (global score 0-4). Results reported as mean ± SD across global score and three subscales (physical, psychological, everyday life). Higher scores indicate greater impairment.	Measured at telephone interview, within one week of clinic visit
Mean daily protein intake	Mean daily protein intake assessed by 24-hour dietary recall. Adequacy evaluated against Nordic Nutrition Recommendations 2023. Results reported as mean ± SD. Data will be used to describe nutritional status in this patient population and to inform the design of the future full-scale study. Unit of Measure: g/kg body weight/day	Measured at baseline clinic visit

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Muscle strength	Handgrip strength (kg) assessed by dynamometer (highest of three attempts, dominant hand). Results reported as mean ± SD and compared to age- and sex-adjusted normative reference values.	Measured at baseline clinic visit
Mobility and physical activity	Physical activity and mobility will be assessed by the Life-Space Assessment (LSA-DK) questionnaire (score 0-120). Results reported as mean ± SD and distribution across mobility categories per standard LSA-DK scoring bands.	Measured at telephone interview, within one week of clinic visit
Staff-reported feasibility	Description: Staff-reported feasibility assessed by qualitative interviews conducted after the inclusion period. Findings reported as a thematic summary of perceived barriers and facilitators. Unit of Measure: Thematic summary (qualitative)	Following completion of inclusion period, approximately 3 months

Collaborators and Investigators

• Sponsor: Hvidovre University Hospital
• Collaborators: The Novo Nordic Foundation; Copenhagen University Hospital, Hvidovre
• Investigators: Principal Investigator: Pia S Jensen, PhD, Outpatient clinic at the Department of Orthopedic Surgery, Hvidovre University Hospital

Publications and helpful links

General Publications

• Cederholm T, Jensen GL, Correia MITD, Gonzalez MC, Fukushima R, Higashiguchi T, Baptista G, Barazzoni R, Blaauw R, Coats A, Crivelli A, Evans DC, Gramlich L, Fuchs-Tarlovsky V, Keller H, Llido L, Malone A, Mogensen KM, Morley JE, Muscaritoli M, Nyulasi I, Pirlich M, Pisprasert V, de van der Schueren MAE, Siltharm S, Singer P, Tappenden K, Velasco N, Waitzberg D, Yamwong P, Yu J, Van Gossum A, Compher C; GLIM Core Leadership Committee; GLIM Working Group. GLIM criteria for the diagnosis of malnutrition - A consensus report from the global clinical nutrition community. Clin Nutr. 2019 Feb;38(1):1-9. doi: 10.1016/j.clnu.2018.08.002. Epub 2018 Sep 3.
• Barnes JA, Eid MA, Creager MA, Goodney PP. Epidemiology and Risk of Amputation in Patients With Diabetes Mellitus and Peripheral Artery Disease. Arterioscler Thromb Vasc Biol. 2020 Aug;40(8):1808-1817. doi: 10.1161/ATVBAHA.120.314595. Epub 2020 Jun 25.
• Teresi JA, Yu X, Stewart AL, Hays RD. Guidelines for Designing and Evaluating Feasibility Pilot Studies. Med Care. 2022 Jan 1;60(1):95-103. doi: 10.1097/MLR.0000000000001664.
• Armstrong DG, Tan TW, Boulton AJM, Bus SA. Diabetic Foot Ulcers: A Review. JAMA. 2023 Jul 3;330(1):62-75. doi: 10.1001/jama.2023.10578.
• Knudsen JT, Johansen CW, Hansen AO, Eshoj HR. The Danish wound-quality of life (Wound-QoL) questionnaire: Translation and psychometric properties. Wound Repair Regen. 2021 Nov;29(6):973-984. doi: 10.1111/wrr.12957. Epub 2021 Jul 13.
• Pedersen MM, Kjaer-Sorensen P, Midtgaard J, Brown CJ, Bodilsen AC. A Danish version of the life-space assessment (LSA-DK) - translation, content validity and cultural adaptation using cognitive interviewing in older mobility limited adults. BMC Geriatr. 2019 Nov 15;19(1):312. doi: 10.1186/s12877-019-1347-0.
• Tobberup R, Jager-Wittenaar H, Sorensen J, Kopp LHP, Svarstad P, Saetre P, Ottery FD. Translation and cultural adaptation of the scored Patient-Generated Subjective Global Assessment (PG-SGA(c)). Clin Nutr ESPEN. 2022 Feb;47:215-220. doi: 10.1016/j.clnesp.2021.12.012. Epub 2021 Dec 17.
• Da Porto A, Miranda C, Brosolo G, Zanette G, Michelli A, Ros RD. Nutritional supplementation on wound healing in diabetic foot: What is known and what is new? World J Diabetes. 2022 Nov 15;13(11):940-948. doi: 10.4239/wjd.v13.i11.940.
• Moore ZE, Corcoran MA, Patton D. Nutritional interventions for treating foot ulcers in people with diabetes. Cochrane Database Syst Rev. 2020 Jul 17;7(7):CD011378. doi: 10.1002/14651858.CD011378.pub2.

Study record dates

Study Major Dates

• Study Start (Estimated): June 2, 2026
• Primary Completion (Estimated): September 30, 2026
• Study Completion (Estimated): October 30, 2026

Study Registration Dates

• First Submitted: May 19, 2026
• First Submitted That Met QC Criteria: May 29, 2026
• First Posted (Actual): June 2, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 29, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Wound healing; DFU; outpatient; Malnutrition; Nutritional assessment; hard-to-heal ulcer
• Additional Relevant MeSH Terms: Endocrine System Diseases; Vascular Diseases; Cardiovascular Diseases; Nutrition Disorders; Diabetes Mellitus; Diabetic Angiopathies; Diabetes Complications; Skin Diseases; Skin Ulcer; Leg Ulcer; Diabetic Neuropathies; Foot Diseases; Nutritional and Metabolic Diseases; Skin and Connective Tissue Diseases; Malnutrition; Diabetic Foot; Foot Ulcer; Health Care Quality, Access, and Evaluation; Investigative Techniques; Epidemiologic Methods; Data Collection; Health Care Evaluation Mechanisms; Quality of Health Care; Public Health; Environment and Public Health; Epidemiologic Measurements; Nutrition Assessment
• Other Study ID Numbers: HvidovreUH_p-2025-19880; NNF19OC0058628 (Other Grant/Funding Number: Novo Nordisk Foundation); p-2025-19880 (Registry Identifier: Danish Data Protection Agency); F-25076787 (Registry Identifier: Scientific Ethics Committee, Capital Region Denmark)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Anonymised study data may be shared with Danish researchers working within the same field, subject to the establishment of a formal data sharing agreement in accordance with the Danish Act on Processing of Personal Data (Databeskyttelsesloven) and the General Data Protection Regulation (GDPR). Data sharing will not be initiated prior to the completion of such an agreement.

Study Data/Documents

1. Study Protocol
   Information identifier: Projekt SNAK
   Information comments: No additional material is available at this time.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No