Introduction
Diabetes mellitus refers to a group of metabolic disorders having chronic hyperglycemia which is either secondary to defective release of insulin from beta cells of pancreas, defect in insulin action on target receptors present in target tissues or both.1 Insulin in pancreas is produced by the β-cells. The pathophysiology of Diabetes mellitus involves progressive loss or dysfunction of pancreatic β-cells resulting in pathological changes to the microvasculature. In Type 1 Diabetes mellitus, there is T-cell mediated autoimmune damage of β cells, while In Type 2 Diabetes mellitus, there are two insulin-related anomalies: insulin resistance and β-cell dysfunction. In early stages, decreased insulin sensitivity triggers β-cells hyperfunction to achieve compensatory increase in insulin secretion to maintain normoglycemia. But overtime, β-cell function begins to decline resulting in insulin deficiency and hyperglycemia.2
As per the International Diabetes Federation Diabetes Atlas 10th edition, in 2021, approximately 537 million adults (20-79 years) in the world were living with diabetes with a estimated rise to 643 million by 2030 and 783 million by 2045 respectively. Diabetes related healthcare expenditure in 2021 was estimated to be $ 966 billion, and projected to reach $ 1054 billion by 2045.3
The Sustainable Development Goals (SDGs), setup in 2015 by United Nations General Assembly (UNGA) include a target to reduce premature deaths due to non-communicable diseases (NCDs), including diabetes, by one third by 2030. The National Health Policy 2017 of India has set a goal to reduce premature deaths from diabetes by 25% by 2025. 4
In order to prevent and control major non-communicable diseases including Diabetes, National Another Programme (National Prevention and Control of Cancer, Diabetes, Cardiovascular Diseases and Stroke) to prevent and control major non- communicable diseases including Diabetes was launched in 2010 by Government of India under National Health Mission (NHM). This programme aims to prevent and control common non-communicable diseases including diabetes by increasing community awareness, facilitating early detection of undiagnosed cases, and linking the identified cases with the health system for follow-up and continuity of care.5
Diabetes-related complications affect many organ systems including skin and are responsible for significant morbidity and mortality. Diabetes chronic complications can either be microvascular ( retinopathy, neuropathy and nephropathy) as well as macrovascular (stroke, cardiovascular disease, peripheral arterial disease) with former having greater prevalence than latter.6
Diabetes mellitus is associated with skin involvement in 79.2 % individuals. Commonest skin manifestations in diabetes include cutaneous infections (47.5%), xerosis (26.4%), and inflammatory skin diseases like granuloma annulare, diabetic blisters etc. (20.7%). Cutaneous manifestations can appear as the first sign of diabetes or may develop at any time in the course of the disease.7 NailfoldCapillaroscopy is a rapid, highly specific and reproducible investigation which involves visualisation of nailfold capillaries. To be strictly accurate, the structures visualised in capillaroscopy are not the capillaries themselves, the thin walls of which are transparent, but instead column of red blood cells. The different techniques for doing capillaroscopy are Widefield stereomicroscopy, High magnification videocapillaroscopy and handheld devices like – ophthalmoscopes, USB microscopes, dermatoscope.8
Capillaroscopy using bimicroscope or operating microscope often necessitates referral to some specialised center. Ophthalmoscope too has been advocated for capillaroscopy but has limitation of field being too small for proper investigation. Dermatoscope has a relatively large field of view and offers a simple, quick and inexpensive method to do nail fold capillaroscopy.9 Moreover, the results of capillaroscopy using dermoscope are equivalent if not better than standard capillary microscopy.10
Recently, it has been suggested that dermoscopy being simple, fast, non-invasive, portable and inexpensive tool can replace capillaroscopy for detection of nailfold abnormalities in systemic diseases.11
Materials and Methods
This was a comparative observational study conducted over a period of 12 months (1ST NOV 2020 TO 31ST OCT 2021) in Government Medical College Jammu and associated hospitals after taking Institutional ethical committee clearance and informed consent from each participant prior to the start of the study. 2 groups of 100 participants each: diabetics and normal healthy indivduals were studied. All the patients who were diagnosed with Diabetes mellitus attending Dermatology/Endocrinology OPD of Government Medical College, Jammu were included regardless to age, sex, ethnic origin and occupation. Comparison group comprised healthy individuals without any comorbidities including diabetes mellitus. All the diabetic patients were of Type 2 diabetes mellitus. A predesigned proforma was used to record relevant history and clinical findings in the patients. The latest HbA1c of all diabetic patients was also noted. Patients with Connective tissue diseases, systemic diseases like hypertension which cause retinopathy and vasculopathy in nailfolds, pregnant women, patients with sepsis or organ dysfunction (liver/kidney/heart), smokers, patients having history or evidence of onychophagia, onychotillomania, trauma, nail infections and recent manicure were excluded from the study.
Nailfold capillaroscopy (NFC) examination
Dermoscopic examination
Dermoscopic examination was done using DermLite DL4 which is 4th generation handheld DermLitedermoscope with features of two brightness levels, a larger field of view using a 30 mm lens, 10x zoom and is 25% smaller than the previous generation. While doing direct skin contact, DL4’s IceCap® is used. It can attach to glass faceplate and greatly reduces the risk of cross-contamination. The phone Redmi K20 Pro was used in the study to click the images and keep the photographic record. Ultrasound Jelly was used as Interface medium as it improved visualization of proximal nailfold capillaries and its greater viscosity than other interface media made it the ideal choice. [Figure 1]
Technique of Nailfoldcapillaroscopy (NFC)12
All patients selected for nailfoldcapillaroscopy examination were made to sit for 15-20 minutes in a room having normal ambient temperature (20-22ºC). Both hands were placed over a dull non-refractile surface at the level of heart. Ultrasound Jelly was placed over proximal nailfold. Then the dermoscope with IceCap attached, was placed over it at an appropriate angle but not pressed to avoid blanching of the blood vessels. Proximal Nailfold capillaries of 8 fingers (excluding thumbs) were examined first at 10x and them image zoomed upto 100x for noting qualitative changes if any. At least 1 sharply focused image in JPEG format of each digit’s nailfold capillaries was clicked for future analysis.
Quantitative parameter i.e. Mean Capillary Density was calculated by analysis of 4th and 5thfingers of both hands. These two fingers were chosen because of the high transparency and being less prone to day-to-day trauma. With the help of 1 mm markings seen in images clicked by DermLite DL4, quantitative analysis was done. All the qualitative findings noted were entered in the proforma both at the time of examination. [Figure 2]
NFC & COVID-19 pandemic:13
Surface of the table was kept clean using 70% isopropyl alcohol and patient was asked to wash hands or use hand sanitizer before performing NFC. IceCap used was frequently changed after few examinations and disinfected with 70% isopropyl alcohol in each examination. An effort was made to minimize the duration of procedure. That’s why thumbs were not examined in the study. The following NFC parameters were recorded:
Quantitative parameters: Mean capillary density was calculated as the number of distal most capillary loops in 4th and 5thfingers of both the hands per millimeter.
Qualitative parameters: The various capillaroscopic abnormalities (mentioned in table below) were carefully visualized and recorded.
Table 1
Definition of various qualitative abnormalities observed in NFC. 14
Subpapillary plexus visibility was also evaluated in proximal nail fold which lies just beneath the dermal papillae in skin. Bushy capillaries were counted under Neoangiogenesis. Also, definition of Neoangiogenesis is broad and indicates new vessel formation in the form of abnormal shapes seen in NFC (other shapes than hairpin, tortuous, or crossing). 15
Statistical analysis
The Categorical variables were presented in the form of number and percentage (%) while the quantitative data was presented as the means ± SD and as median with 25th and 75th percentiles (interquartile range).The comparison of the variables which were quantitative in nature was analyzed using Independent t test (for two groups) and ANOVA test (for more than two groups) and variables which are qualitative in nature was analyzed using Chi-Square test. If any cell had an expected value of less than 5 then Fisher’s exact test was used. For statistical significance, p value of less than 0.05 was considered statistically significant.
Results
Distribution of gender was comparable between patients with diabetes mellitus and healthy individuals in our present study having p value=1. Mean ± SD of age (years) in patients with diabetes mellitus was 47.94 ± 9.52 and healthy individuals was 45.42 ± 9.91 with no significant difference between them. (p value=0.068). (Table 2)
Mean ± SD of mean capillary density(capillaries/mm) in patients with diabetes mellitus was 6.69 ± 0.37 which was significantly lower as compared to healthy individuals (7.23 ± 0.38).(p value <.0001). Proportion of patients with tortuous capillary was remarkably higher in patients of diabetes as compared to healthy controls (p value <0.0001). (Figure 3)
Proportion of patients having receding capillary (48% vs 11% respectively) was significantly higher in diabetic as compared to healthy individuals with p value <0.0001 (Figure 4). Proportion of patients with capillary dilation was also greater in diabetics as compared to healthy individuals (46% vs 19% respectively). (p value <0.0001). (Figure 5)
Distribution of variables like meandering capillary (Absent:- 62% vs 71% respectively, Present:- 38% vs 29% respectively) (p value=0.178) and bushy capillary was comparable between both the groups(Absent:- 94% vs 95% respectively, Present:- 6% vs 5% respectively) (p value=0.756). (Table 3, Figure 6)
Proportion of patients having neoangiogenesis (27% vs 7% respectively) (p value=0.0002) and avascular areas was significantly higher in diabetics as compared to healthy individuals(21% vs 3% respectively). (p value=0.0001) (Table 4,Figure 7)
Proportion of patients with capillary dropout was higher in patients with diabetes as compared to healthy population (30% vs 17% respectively). (p value=0.03) (Table 5 ). Distribution of microhemorrhages (p value= 1) and angulated capillary (p value=0.171) was comparable between patients of diabetes mellitus and healthy individuals. (Table 6). Proportion of patients having bizarre capillary was comparatively higher in patients of diabetes as compared to healthy individuals (16% vs 3% respectively). (p value=0.003) (Table 7). Distribution of subpapillary plexus visibility was comparable between patients and healthy individuals. (Absent:- 75% vs 81% respectively, Present:- 25% vs 19% respectively) (p value=0.306). (Table 8,Figure 8)
Figure 1
Equipments: 1: Phone; 2: Dermoscope; 3: IceCap; 4: Universal Smartphone Adapter; 5: Ultrasound Jelly
Figure 2
Nailfold capillaroscopy in a healthy individual, Showing 1 mm black markings and method of ascertaining 4 mm distance to calculate mean capillary density as explained in the methodology.
Table 2
Comparison of demographic characteristics between diabetes mellitus and healthy individuals.
Table 3
Comparison of meandering and bushy capillary between diabetes mellitus and healthy individuals.
Table 4
Comparisonof neoangiogenesis and avascular areas between diabetes mellitus and healthyindividuals.
Table 5
Comparison of capillary dropout between diabetes mellitus and healthy individuals.
|
Capillary dropout |
Diabetes mellitus (n=100) |
Healthy individuals (n=100) |
Total |
P value |
|
Absent |
70(70%) |
83(83%) |
153(76.50%) |
0.03‡ |
|
Present |
30(30%) |
17(17%) |
47(23.50%) |
|
|
Total |
100(100%) |
100(100%) |
200(100%) |
Table 6
Comparison of microhemorrhages and angulated capillaries between diabetes mellitus and healthy individuals.
Table 7
Comparison of bizarre capillary between diabetes mellitus and healthy individuals.
Table 8
Comparison of subpapillary plexus visibility between diabetes mellitus and healthy individuals.
Discussion
The microvascular changes associated with diabetes mellitus have also been shown to affect nailfold capillaries which are horizontally oriented capillaries parallel to the skin in proximal nailfold. 16
With an increasing availability of high-quality dermatoscopes, it is possible to evaluate nailfold capillary microvascular changes in a faster and reliable way.14 Hand-held dermatoscopes is a device which offers low magnification (upto 10x in DermLite DL4) but excellent optical resolution and images. Also, they are easy to use and can be easily connected to smartphones. So, they are a better device from practical point of view making them a preferred choice over videodermatoscopes (used for research purposes) in real world scenario. 12
In this study, nailfoldcapillaroscopy was done using hand-held dermatoscope in 100 diabetics and 100 healthy normal individuals were evaluated in the comparison group. 50 diabetics also had microvascular complication in the form of diabetic retinopathy (DR) and 50 had no retinopathy. In study by Jakhar et al 96 diabetics (46 with microvascular complications and 50 without) and 40 healthy controls were studied.
In our present study, gender distribution was comparable between diabetics and healthy individuals. (Female: - 49% vs 49% respectively, Male:- 51% vs 51% respectively) (p value=1). In contrast, study done by Mohanty et al. 17 had male predominance with 64.8% males and 35.2% females respectively among 250 diabetic patients. Mean ± SD of age (years) in patients with diabetes mellitus was 47.94 ± 9.52 and healthy individuals was 45.42 ± 9.91 with statistically no significant difference between them. (p value=0.068). This is similar to study conducted by Lima et al 18 with no remarkable difference (p value = 0.12) between the two groups.
Mean ± SD of mean capillary density i.e. MCD (capillaries/mm) in patients with diabetes mellitus was 6.69 ± 0.37, which was significantly lower as compared to healthy individuals (7.23 ± 0.38).(p value <.0001). The results were similar to study conducted by Lima et al 18which showed significant reduction in MCD in diabetics 6.12 (5.5-7.0) vs 7.12 (7.0-7.4) in controls.(p value <0.0001). Barchetta et al19 in his study has reported that 10.7% of type 2 diabetics have a MCD <8 capillaries/mm.
The qualitative capillary changes observed in healthy controls were Tortuosity (30%), meandering capillary (29%), microhemorrhages (27%), sub papillary plexus visibility (19%), dilated capillary (19%) etc. Similar observations have been made in literature as well by Jakhar et al, Dolezalova, Martino et al. 14, 20, 21
In the present study, proportion of patients with tortuous capillary was notably higher in patients of diabetes as compared to healthy individuals (64% vs 30% respectively). Proportion of patients having receding capillary and capillary dilation was also noteworthy in diabetics as compared to healthy individuals.
Proportion of patients with neoangiogenesis was remarkably higher in diabetics as compared to healthy individuals (27% vs 7% respectively). Proportion of patients having avascular area, capillary dropouts and bizarre capillary was also higher in patients of diabetes mellitus as compared to healthy controls. Capillaroscopic parameters like meandering capillary (p value=0.178), bushy capillary (p value=0.756), microhemorrhage (p value=1), angulated capillary (p value=0.171) and subpapillary plexus visibility (p=0.306) were not significant in diabetics in comparison to healthy individuals.
Thus, in nail fold capillaroscopic changes in our study, the statistically significant findings noted among diabetics were tortuous capillaries, receding capillaries, capillary dilation, capillary dropouts, neoangiogenesis, avascular areas and bizarre capillaries. Angulated capillaries as reported by Jakhar et al14 were found more commonly in diabetic patients than the healthy individuals .
The study by Uyar et al22 showed in diabetic patients tortuosity, bushy capillary, neoangiogenesis, bizarre capillaries, microhemorrhage, capillary ectasia and aneurysm were significantly increased than healthy controls. Our results are near comparable to this study however bushy capillaries were not significant in our study. In one study by, Lima et al18 he observed increased number of ectasias/dilations and increased presence of avascular areas. These observations are similar to our study.
Conclusion
Significant nail fold capillaroscopic changes were seen in patients of diabetes in comparison to healthy individuals. NFC using dermatoscope is a quick, easy to perform, safe and cost effective technique to detect early changes in the micro vascular bed which can be used to assess severity of disease. Our results suggest that it could possibly become a useful tool in diabetics to diagnose as well as monitor various micro vascular complications in the future.
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