Efficacy and Safety of Topical or Oral Hydrolyzed Collagen in Women with Dermatoporosis: A Randomized, Double-Blind, Factorial Design Study

Skin aging was considered for years an aesthetic concern but with the increase in life expectancy, the functional impact of aging has been emphasized [1, 2]

Bateman’s purpura was described in 1836 as a marker of photoaging and is characterized by hemorrhagic areas, purpuric lesions, confluent petechiae or ecchymoses, stellate scars, and thinning skin [3]. The conception of dermatoporosis (DP) includes functional consequences of skin aging and the potential risks associated with skin atrophy and fragility [4]. The term DP was proposed by Saurat in 2007 and defines the chronic skin failure syndrome, which resembles osteoporosis, such as structural weakness due to aging, the occurrence of complications, and the need for preventive measures [2].

Clinical manifestations of DP include morphological alterations (cutaneous atrophy, senile purpura, and stellate pseudoscars) and functional consequences of skin fragility resulting from minimal trauma (lacerations and dissecting hematoma), which compromises the quality of life of these patients (Fig. 1).

In vivo high frequency ultrasound (20 MHz), and reflectance confocal microscopy are useful tools to evaluate the degrees of DP, instead of skin biopsy, in clinical practice [5].

Advanced age is the main risk factor for DP and patients older than 85 years have a more than twofold increased risk versus younger patients [5]. A cross-sectional study conducted in France revealed a prevalence of DP in 32% of patients older than 60 years [6], and Saurat el al. [4] estimated the prevalence at 37.5% in patients aged 65 years and older, reaching up to 51.9% of the population aged over 80 years.

Other risk factors include chronic actinic damage or photoaging, genetic susceptibility or intrinsic aging, and chronic use of topical or systemic corticosteroids [7]. Chronic renal failure is also a relevant factor and increases the risk of DP by up to five times, regardless of age [6]. Other factors, such as diabetes, anticoagulant use, and solar exposure have been associated with DP and cutaneous atrophy [4]. In regard to diet, higher intake of carbohydrates is capable of damaging the skin structure through nonenzymatic glycation, the covalent attachment of sugar to a protein with production of advanced glycation end products (AGEs) [8].

Currently, there are no specific measures adopted in dermatological practice that resulted as highly efficient to prevent or revert DP [2]. The ideal intervention should be well tolerated, inexpensive, and with few adverse events. There is no robust evidence of the benefit of oral treatment for DP. In postmenopausal women, some studies have shown an increase in skin thickness after hormone replacement therapy [9‐12]. Clinical trials have shown benefits of oral hydrolyzed collagen (HC) in skin aging, such as improved elasticity, hydration, density of the dermis, and collagen content [13‐18].

Hydroxyproline is a collagen-specific amino acid, and the main peptide found in plasma after ingestion of HC is proline-hydroxyproline, which functions as a trigger for collagen synthesis and extracellular matrix reorganization. The mechanism of action of HC is a chemotactic stimulus for fibroblasts with attraction of cells to repair tissue damage [14].

Oral treatments for skin aging control, such as oral isotretinoin, hyaluronan and “senolytics” or mTOR inhibitors (metformin, rapamicin) have been discussed; despite that, the studies are not conclusive. [19‐22]

To date, there are no studies concerning topical HC formulations. Topical hyaluronic acid creams (50–400 kDa) improved skin atrophy [23], and the combination of hyaluronic acid and retinaldehyde also reduced senile purpura [24‐27]. A randomized comparative trial between tretinoin cream 0.05% and oral isotretinoin showed increase in epidermal thickness, reduction of elastosis, increase in dermal collagen I, and decreased protein p53 expression, with no difference between treatments. [28]. Vitamin C 5% cream improved elasticity and skin thickness in elderly patients with Bateman’s purpura [03].

To date, there is no proven oral or topical treatment for DP. Retinoids and glycolic acid are useful topical treatment to improve skin atrophy and fragility [28].

The aim of this study was to assess the efficacy and safety of oral and/or topical HC on clinical, quality of life, histological, immunohistochemical, viscoelastic, and ultrasound parameters.

IRB approval status: Reviewed and approved by UNiFESP IRB (848/2015) – approval # 1.282.133. Standardized photographs were taken by Lais RS Guadanhim.Dr Fernanda Caramella participated in histologic and immunohistochemistry evaluation. Independent photographic evaluation was performed by Drs Gisele Jacobino Nunes, Juliana Mossini Nicoliello. This studied reviewed and approved by UNIFESP. IRB (848/2015) – approval # 1.282.133 and was performed in accordance with the Helsinki Declaration of 1964 and its later amendments. All subjects provided informed consent to participate in the study.

This was a randomized, double-blind, placebo-controlled, parallel, and factorial study of therapeutic intervention to assess the efficacy and safety of topical and/or oral HC in postmenopausal women with DP.

The study population included eligible women aged over 60 years with mild DP (stage I) of the forearms. Exclusion criteria were procedures, topic or oral treatments for photoaging of the forearms in the past 3 months, patients with secondary DP or with causes for its aggravation (smoking, chronic renal failure, diabetes, chronic corticosteroid use, use of anticoagulant medication, even acetylsalicylic acid), solid organ transplantation, presence of photodermatosis, inflammatory or infectious skin disease in the forearms, chemotherapy, and immunosuppression and hormone replacement therapy. The study was conducted in the outpatient clinic of a public hospital in São Paulo, Brazil, from June 2016 to April 2018.

The unit of analysis for this study was each forearm. The data were tested for normality using the Shapiro–Wilk test. The variables were represented as mean and standard deviation (SD). The analysis was conducted in a factorial manner, that is, the effect of the oral, the topic, and whether there was interaction between oral and topic was measured. Data were compared between groups and according to visits. The data were compared according to time and groups over time, using a linear mixed effects (hierarchical) model with a robust covariance matrix, and probability adjustment for each distribution. Post hoc analysis was performed using the Šidák correction. Statistical analysis was performed blindly to the groups, using the software IBM SPSS 25v.

To estimate sample size we assumed mean baseline histologic collagen density as 41% (SD 7%) as the main outcome and expected an increase over 10% for one of the groups, with a power of 90% and an alpha of 5%, and thus expected a sample size of 56.

A total of 56 patients, aged from 60 to 93 years with DP stage I were included. The mean age was 69.53 years (SD 7.33) and 46/56 (82.14%) of patients were phototype III. No participant developed activities under direct sun exposure. There were three dropouts, two from the placebo group, due to reasons not related to the treatment.

Regarding histological findings (Table 1), there were no increases promoted by topical or oral treatments in the thickness of the epidermis and density of collagen and elastin. On the contrary, total collagen was reduced in the oral HC groups. All groups but oral and topical HC saw the upper dermal elastin reduced. By using the high frequency ultrasound images and digital analysis, it was observed that the average measurements of echogenicity, thickness and pixel intensity of total and upper dermis did not show an increase between the observed times. None of the groups obtained a consistent temporal gain in the parameters in the observed periods, but a reduction in pixel intensity and echogenicity were evidenced in the oral HC groups (Table 2).

The measures of viscoelastic properties of the skin, according to groups, did not show increase sustained until V7 (Table 3).

A low impact in the QoL was detected at baseline (mean DLQI 2.2). All treatments reduced the DLQI score (mean 0.6; p < 0.01), with no difference among the groups (p = 0.65).

The clinical blinded evaluation performed by the main investigator and two independent dermatologists observed no difference in general aspect of the skin and lesions characteristics of DP by comparing standardized photos of both forearms (at baseline and after 24 weeks) (Fig. 2).

There is a progressive reduction in collagen production and an increase in its degradation due to higher expression of metalloproteinases (MMPs) by intrinsic aging. This process is aggravated by extrinsic aging caused mainly by chronic and uncontrolled exposure to UVA and UVB radiation, smoking, hormones, chronic diseases, diet, and pollution, among others [29, 30].

Previous studies suggested that oral hydrolyzed collagen (HC) supplementation can promote collagenesis and elastogenesis in the skin. Preclinical data demonstrated potential benefits of HC on the metabolism of extracellular matrix proteins, as well as positive impact on barrier function, hydration, and improvement of skin elasticity [13, 31‐33].

HC is considered a safe ingredient, with good tolerability profile and, to date, there are no studies on its topical use.

DP is a prevalent condition affecting up to 35% of the elderly population, and there are still no evidence-based specific strategies for its prevention and treatment. The impact of chronological aging appears to be lower than that caused by extrinsic factors such as chronic sun exposure, use of corticosteroids, anticoagulants, and the presence of renal failure. In this study, the presence of comorbidities and the use of drugs that potentially aggravate DP were exclusion criteria.

Despite the longer supplementation time (24 weeks) and the higher dose of HC (5 g/day), the histological and immunohistochemical parameters did not reveal an increase in the amount of total collagen, collagen I, and elastin biomarkers, which differs from a previous study where HC supplementation (2.5 g/day) for just 8 weeks increased procollagen I by 65% and elastin by 18% [15]. It should be highlighted that the authors performed these measurements by using the ELISA test in the fluid of skin blisters obtained by suction in periocular area. That methodology is not comparable with ours as we have used punch biopsy in forearms of all patients and immunohistochemical biomarkers for detection of tissue collagen and elastin. Moreover, we have included older patients in our study (older than 60 years versus 45–65 years old) which may contribute to poorer intestinal absorption and more advanced fibroblast senescence.

Proksch et al. [14] evaluated skin elasticity after 8 weeks of supplementation with HC and found an average increase of 7%, with better results in elasticity parameters in patients aged over 50, which motivated our evaluation of patients over 60 years old. However, the authors did not mention if this result was sufficient for clinical observation of improvement in skin elasticity. In the present study, some viscoelastic parameters showed an increase after 12 weeks in patients treated with HCo, but returned to baseline values at week 24. In parameter R2, the positive impact seemed greater in patients treated with HCo associated or not with HCt. In parameter R5, the use of HCt had an additional positive effect on patients using HCo or Po after 12 weeks. In parameter R6, patients in the Po group performed better when treated with HCt at 12 weeks, with return to baseline values at week 24. These findings may be explained by the possibility of irregular use of study products after a period of time, which is understandable when participants are unable to see improvement. They also illustrate the limitations of noninvasive instrumental measures, particularly in skin viscoelastic properties.

There is still no well-established consensus on the meaning of ultrasound changes as a parameter for pre- and post-treatment assessment. Different studies suggest variable interpretations for improvement, such as increase in total, upper, or lower dermis echogenicity, reduction in echogenicity, and in the rate of low echogenicity pixels of the upper and lower dermis [35, 36].

In contrast to what was described in the literature, i.e., an increase of 8.8% of dermal echogenicity [13] and collagen density in the dermis after 12 weeks, no difference in the average measurements of echogenicity and thickness and pixel intensity of upper and total dermis after 24 weeks of supplementation was detected in our study. None of the groups showed a temporal gain in these parameters. Furthermore, the high heterogeneity of the results and publication bias were indicated by a recent meta-analysis in oral HC [37].

There was improvement in the QoL and in the general appearance of the skin in the opinion of patients in all groups, which is probably due to regular monitoring and the hydration effect promoted by the use of the serum. Patients’ acceptance of supplementation was good and, according to their opinions, there was improvement in several aspects, such as skin hydration and smoothness, reduction of wrinkles, improvement in nails, hair quality, genital lubrication, and joint pain, despite no difference among the groups.

Throughout the follow-up, the patient who reported the greatest clinical improvement was the oldest patient (aged 93 years). This patient reported benefits in dryness and thinning of the skin of both forearms. At the end of the study, we found out that this patient  had received just oral placebo and there was no difference between the forearms, which reinforces the role of the placebo effect in clinical trials and the importance of using moisturizers (even only a topical serum vehicle) in fragile skin. The so-called Hawthorne effect could also explain this fact, in which the intensive follow-up of the clinical trial helps patients evolve better, regardless of the intervention [38].

Larger studies to confirm our findings are warranted.

In postmenopausal women with stage I dermatoporosis, oral or topical collagen peptides, used alone or in combination, have no benefits on forearm skin after 6 months of intervention, and therefore should not be used routinely in this population.