Teenage acne and cancer risk in US women: A prospective cohort study

Bioprospecting the Skin Microbiome: Advances in Therapeutics and Personal Care Products

Bioprospecting is the discovery and exploration of biological diversity found within organisms, genetic elements or produced compounds with prospective commercial or therapeutic applications. The human skin is an ecological niche which harbours a rich and compositional diversity microbiome stemming from the multifactorial interactions between the host and microbiota facilitated by exploitable effector compounds. Advances in the understanding of microbial colonisation mechanisms alongside species and strain interactions have revealed a novel chemical and biological understanding which displays applicative potential. Studies elucidating the organismal interfaces and concomitant understanding of the central processes of skin biology have begun to unravel a potential wealth of molecules which can exploited for their proposed functions. A variety of skin-microbiome-derived compounds display prospective therapeutic applications, ranging from antioncogenic agents relevant in skin cancer therapy to treatment strategies for antimicrobial-resistant bacterial and fungal infections. Considerable opportunities have emerged for the translation to personal care products, such as topical agents to mitigate various skin conditions such as acne and eczema. Adjacent compound developments have focused on cosmetic applications such as reducing skin ageing and its associated changes to skin properties and the microbiome. The skin microbiome contains a wealth of prospective compounds with therapeutic and commercial applications; however, considerable work is required for the translation of in vitro findings to relevant in vivo models to ensure translatability.

Network Pharmacology and Molecular Modeling to Elucidate the Potential Mechanism of Neem Oil against Acne vulgaris

Acne vulgaris is a common skin disorder with a complicated etiology. Papules, lesions, comedones, blackheads, and other skin lesions are common physical manifestations of Acne vulgaris, but the individual who has it also regularly has psychological repercussions. Natural oils are being utilized more and more to treat skin conditions since they have fewer negative effects and are expected to provide benefits. Using network pharmacology, this study aims to ascertain if neem oil has any anti-acne benefits and, if so, to speculate on probable mechanisms of action for such effects. The neem leaves (Azadirachta indica) were collected, verified, authenticated, and assigned a voucher number. After steam distillation was used to extract the neem oil, the phytochemical components of the oil were examined using gas chromatography-mass spectrometry (GC-MS). The components of the oil were computationally examined for drug-likeness using Lipinski's criteria. The Pharm Mapper service was used to anticipate the targets. Prior to pathway and protein-protein interaction investigations, molecular docking was performed to predict binding affinity. Neem oil was discovered to be a potential target for STAT1, CSK, CRABP2, and SYK genes in the treatment of Acne vulgaris. In conclusion, it was discovered that the neem oil components with PubChem IDs: ID_610088 (2-(1-adamantyl)-N-methylacetamide), ID_600826 (N-benzyl-2-(2-methyl-5-phenyl-3H-1,3,4-thiadiazol-2-yl)acetamide), and ID_16451547 (N-(3-methoxyphenyl)-2-(1-phenyltetrazol-5-yl)sulfanylpropanamide) have strong affinities for these drug targets and may thus be used as therapeutic agents in the treatment of acne.

Genome-wide association meta-analysis identifies 29 new acne susceptibility loci

Acne vulgaris is a highly heritable skin disorder that primarily impacts facial skin. Severely inflamed lesions may leave permanent scars that have been associated with long-term psychosocial consequences. Here, we perform a GWAS meta-analysis comprising 20,165 individuals with acne from nine independent European ancestry cohorts. We identify 29 novel genome-wide significant loci and replicate 14 of the 17 previously identified risk loci, bringing the total number of reported acne risk loci to 46. Using fine-mapping and eQTL colocalisation approaches, we identify putative causal genes at several acne susceptibility loci that have previously been implicated in Mendelian hair and skin disorders, including pustular psoriasis. We identify shared genetic aetiology between acne, hormone levels, hormone-sensitive cancers and psychiatric traits. Finally, we show that a polygenic risk score calculated from our results explains up to 5.6% of the variance in acne liability in an independent cohort.

Lifetime Impact of Cow's Milk on Overactivation of mTORC1: From Fetal to Childhood Overgrowth, Acne, Diabetes, Cancers, and Neurodegeneration

The consumption of cow's milk is a part of the basic nutritional habits of Western industrialized countries. Recent epidemiological studies associate the intake of cow's milk with an increased risk of diseases, which are associated with overactivated mechanistic target of rapamycin complex 1 (mTORC1) signaling. This review presents current epidemiological and translational evidence linking milk consumption to the regulation of mTORC1, the master-switch for eukaryotic cell growth. Epidemiological studies confirm a correlation between cow's milk consumption and birthweight, body mass index, onset of menarche, linear growth during childhood, acne vulgaris, type 2 diabetes mellitus, prostate cancer, breast cancer, hepatocellular carcinoma, diffuse large B-cell lymphoma, neurodegenerative diseases, and all-cause mortality. Thus, long-term persistent consumption of cow's milk increases the risk of mTORC1-driven diseases of civilization. Milk is a highly conserved, lactation genome-controlled signaling system that functions as a maternal-neonatal relay for optimized species-specific activation of mTORC1, the nexus for regulation of eukaryotic cell growth, and control of autophagy. A deeper understanding of milk´s impact on mTORC1 signaling is of critical importance for the prevention of common diseases of civilization.

Gender-specific associations between polymorphisms of the circadian gene RORA and cutaneous melanoma susceptibility

BACKGROUND

Melanoma is the deadliest of skin cancers and has an increasing annual incidence worldwide. It is a multi-factorial disease most likely arising from both genetic predisposition and environmental exposure to ultraviolet light. Genetic variability of the components of the biological circadian clock is recognized to be a risk factor for different type of cancers. Moreover, two variants of a clock gene, RORA, have been associated with melanoma patient's prognosis. Our aim is to test the hypothesis that specific single nucleotide polymorphisms (SNPs) of the circadian clock genes may significantly influence the predisposition to develop cutaneous melanoma or the outcome of melanoma patients.

METHODS

We genotyped 1239 subjects, 629 cases of melanoma and 610 healthy controls in 14 known SNPs of seven selected clock genes: AANAT, CLOCK, NPAS2, PER1, PER2, RORA, and TIMELESS. Genotyping was conducted by q-PCR. Multivariate logistic regression was employed for susceptibility of melanoma assessment, modeled additively. Subgroup analysis was performed by gender. For the female subgroup, a further discrimination was performed by age. For prognosis of melanoma assessment, multivariate Cox proportional hazard regression was employed. The Benjamini-Hochberg method was utilized as adjustment for multiple comparisons.

RESULTS

We identified two RORA SNPs statistically significant with respect to the association with melanoma susceptibility. Considering the putative role of RORA as a nuclear steroid hormone receptor, we conducted a subgroup analysis by gender. Interestingly, the RORA rs339972 C allele was associated with a decreased predisposition to develop melanoma only in the female subgroup (OR 0.67; 95% CI 0.51-0.88; P = 0.003) while RORA rs10519097 T allele was associated with a decreased predisposition to develop melanoma only in the male subgroup (OR 0.62; 95% CI 0.44-0.87; P = 0.005). Moreover, the RORA rs339972 C allele had a decreased susceptibility to develop melanoma only in females aged over 50 years old (OR 0.67; 95% CI 0.54-0.83; P = 0.0002). None of the studied SNPs were significantly associated with the prognosis.

CONCLUSIONS

Overall, we cannot ascertain that circadian pathway genetic variation is involved in melanoma susceptibility or prognosis. Nevertheless, we identified an interesting relationship between melanoma susceptibility and RORA polymorphisms acting in sex-specific manner and which is worth further future investigation.

MicroRNA-21-Enriched Exosomes as Epigenetic Regulators in Melanomagenesis and Melanoma Progression: The Impact of Western Lifestyle Factors

DNA mutation-induced activation of RAS-BRAF-MEK-ERK signaling associated with intermittent or chronic ultraviolet (UV) irradiation cannot exclusively explain the excessive increase of malignant melanoma (MM) incidence since the 1950s. Malignant conversion of a melanocyte to an MM cell and metastatic MM is associated with a steady increase in microRNA-21 (miR-21). At the epigenetic level, miR-21 inhibits key tumor suppressors of the RAS-BRAF signaling pathway enhancing proliferation and MM progression. Increased MM cell levels of miR-21 either result from endogenous upregulation of melanocytic miR-21 expression or by uptake of miR-21-enriched exogenous exosomes. Based on epidemiological data and translational evidence, this review provides deeper insights into environmentally and metabolically induced exosomal miR-21 trafficking beyond UV-irradiation in melanomagenesis and MM progression. Sources of miR-21-enriched exosomes include UV-irradiated keratinocytes, adipocyte-derived exosomes in obesity, airway epithelium-derived exosomes generated by smoking and pollution, diet-related exosomes and inflammation-induced exosomes, which may synergistically increase the exosomal miR-21 burden of the melanocyte, the transformed MM cell and its tumor environment. Several therapeutic agents that suppress MM cell growth and proliferation attenuate miR-21 expression. These include miR-21 antagonists, metformin, kinase inhibitors, beta-blockers, vitamin D, and plant-derived bioactive compounds, which may represent new options for the prevention and treatment of MM.

Exogenous hormone use and cutaneous melanoma risk in women: The European Prospective Investigation into Cancer and Nutrition

Evidence suggests an influence of sex hormones on cutaneous melanoma risk, but epidemiologic findings are conflicting. We examined the associations between use of oral contraceptives (OCs) and menopausal hormone therapy (MHT) and melanoma risk in women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC). EPIC is a prospective cohort study initiated in 1992 in 10 European countries. Information on exogenous hormone use at baseline was derived from country-specific self-administered questionnaires. We used Cox proportional hazards regression models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). Over 1992-2015, 1,696 melanoma cases were identified among 334,483 women, whereof 770 cases among 134,758 postmenopausal women. There was a positive, borderline-significant association between OC use and melanoma risk (HR = 1.12, 95% CI = 1.00-1.26), with no detected heterogeneity across countries (phomogeneity = 0.42). This risk increased linearly with duration of use (ptrend = 0.01). Among postmenopausal women, ever use of MHT was associated with a nonsignificant increase in melanoma risk overall (HR = 1.14, 95% CI = 0.97-1.43), which was heterogeneous across countries (phomogeneity = 0.05). Our findings do not support a strong and direct association between exogenous hormone use and melanoma risk. In order to better understand these relations, further research should be performed using prospectively collected data including detailed information on types of hormone, and on sun exposure, which may act as an important confounder or effect modifier on these relations.

Integrated targeted serum metabolomic profile and its association with gender, age, disease severity, and pattern identification in acne

Background

Westernized diet and nutritional metabolism are important in acne pathogenesis, especially in adult patients. However, clinical and basic data are lacking. Pattern identification (PI) is a tool that results in a diagnostic conclusion based on a cluster of concurrent symptoms and signs in traditional medicine. Acne can be classified by PI. However, whether the metabolomic profile differs according to the PI of acne is unknown. Metabolomic data would help clarify the pathogenesis of acne.

Methods

We conducted a cross-sectional study involving 40 healthy controls and 60 subjects with acne. We evaluated androgens, serum lipids, essential amino acids, nonessential amino acids, other amino acids, and pro-inflammatory cytokines of all subjects and compared the metabolomic profiles between acne subjects and healthy controls, and in subgroups according to gender, age, severity, and PI.

Results

Dehydroepiandrosterone sulfate and serum fatty acids were significantly higher in female subjects, adolescents, and those with disharmony of the thoroughfare and conception vessels. The total essential and nonessential amino acids were significantly lower in the overall, female, adult, severe, and phlegm-stasis group. The latter group exhibited elevated serum levels of interleukin-1β and -6.

Conclusions

This is the first study to investigate serum lipids, amino acids, and cytokines in subjects with acne. We analyzed the differences between metabolomic profiles to determine the diagnostic value of PI. Prospective studies with more patients are needed to confirm the characteristics of each PI and lipidomic data will enrich knowledge concerning lipid mechanism.

Potential interaction of inflammatory hyperemia and hyperphosphatemia in tumorigenesis

The present article proposes that the association of inflammation with cancer is potentially mediated by the interaction of inflammatory hyperemia and hyperphosphatemia. Hyperemia increases blood flow rate and blood volume, and hyperphosphatemia is caused by elevated serum levels of dysregulated inorganic phosphate. It is hypothesized that the interaction of inflammatory hyperemia and hyperphosphatemia circulates increased amounts of inorganic phosphate to the tumor microenvironment, where increased uptake of inorganic phosphate through sodium-phosphate cotransporters is sequestered in cells. Elevated levels of intracellular phosphorus increase biosynthesis of ribosomal RNA, leading to increased protein synthesis that supports tumor growth. The present article also proposes that the interaction of inflammatory hyperemia and hyperphosphatemia may help explain a chemopreventive mechanism associated with NSAIDs.

Severe acne and risk of breast cancer

PURPOSE

Hormonal imbalance early in life is thought to be associated with breast cancer risk. Severe acne may arise from hormonal imbalance and could serve as an indicator of increased breast cancer risk. We explored whether severe acne was associated with incident breast cancer.

METHODS

We used data from the Sister Study, a large (n = 50,884) prospective cohort of women who had a sister diagnosed with breast cancer, but who were free of breast cancer themselves at baseline. Participants completed a structured questionnaire that included demographics, lifestyle factors, and medical history, including any diagnosis of severe acne. Adjusted Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs) for the association of severe acne and breast cancer (invasive disease or ductal carcinoma in situ).

RESULTS

During an average of 8.4 years of follow-up, 3049 breast cancer cases were diagnosed. Ever being diagnosed with severe acne was associated with a higher risk of breast cancer (HR 1.23; 95% CI 0.98, 1.54), particularly in women who were diagnosed prior to age 18 years (HR 1.40; 95% CI 1.04, 1.90). Results were similar when limited to invasive cancers.

CONCLUSIONS

Our study supports a non-significant positive association between severe acne-a potential marker of hormonal imbalance-and breast cancer risk. These findings suggest that severe acne, when considered along with other risk factors, could help to identify women who may be at a higher risk of breast cancer.

Host Characteristics and Risk of Incident Melanoma by Breslow Thickness

BACKGROUND

Several host characteristics, including pigmentary traits (hair color, sunburn susceptibility and tanning ability), number of common nevi (moles), and family history of melanoma, have been associated with risk of melanoma.

METHODS

We prospectively examined the associations between host characteristics and risk of incident melanoma by Breslow thickness (≤1 mm, thin melanoma; or >1 mm, "thicker melanoma") based on the Nurses' Health Study (NHS, n = 86,380 women), NHS II (n = 104,100 women), and Health Professionals Follow-up Study (HPFS, n = 46,934 men).

RESULTS

During 22-30 years' follow-up, a total of 1,813 incident melanoma cases were identified with information on Breslow thickness, 1,392 (76.8%) of which had thin melanoma. No significant differences were observed for thin and thicker melanoma in associations with hair color, sunburn susceptibility, and tanning ability. However, we found significant differences for the association with family history of melanoma, with a higher risk estimate for thicker melanoma [HR = 2.55; 95% confidence interval (CI): 1.91-3.42] than thin melanoma (HR = 1.59; 95% CI: 1.21-2.08; P heterogeneity = 0.02). Interestingly, women and men displayed differential associations between nevi count and risk of melanoma by Breslow thickness, with the association appearing stronger for thicker melanoma than thin melanoma in men (P heterogeneity = 0.01), but not in women.

CONCLUSIONS

Individuals with family history of melanoma may be more likely to develop thicker melanoma. Men with high number of common nevi may tend to develop thicker melanoma, which was not found for women.

IMPACT

The findings further stress the risk of thicker melanoma for individuals with a family history of melanoma and men with a high nevi count.

Genetic variants in RORA and DNMT1 associated with cutaneous melanoma survival

Cutaneous melanoma (CM) is considered as a steroid hormone-related malignancy. However, few studies have evaluated the roles of genetic variants encoding steroid hormone receptor genes and their related regulators (SHR-related genes) in CM-specific survival (CMSS). Here, we performed a pathway-based analysis to evaluate genetic variants of 191 SHR-related genes in 858 CMSS patients using a dataset from a genome-wide association study (GWAS) from The University of Texas MD Anderson Cancer Center (MDACC), and then validated the results in an additional dataset of 409 patients from the Harvard GWAS. Using multivariate Cox proportional hazards regression analysis, we identified three-independent SNPs (RORA rs782917 G > A, RORA rs17204952 C > T and DNMT1 rs7253062 G > A) as predictors of CMSS, with a variant-allele attributed hazards ratio (HR) and 95% confidence interval of 1.62 (1.25-2.09), 1.60 (1.20-2.13) and 1.52 (1.20-1.94), respectively. Combined analysis of risk genotypes of these three SNPs revealed a decreased CMSS in a dose-response manner as the number of risk genotypes increased (ptrend  < 0.001); however, no improvement in the prediction model was observed (area under the curve [AUC] = 79.6-80.8%, p = 0.656), when these risk genotypes were added to the model containing clinical variables. Our findings suggest that genetic variants of RORA and DNMT1 may be promising biomarkers for CMSS, but these results needed to be validated in future larger studies.

Tetracycline use and risk of incident skin cancer: a prospective study

Background:

Tetracycline is a photosensitising medication that increases skin vulnerability to UV-related damage.

Methods:

We prospectively examined tetracycline use and risk of incident melanoma, squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) based on 213 536 participants from the Nurses’ Health Study (NHS), NHS2, and Health Professionals Follow-up Study. Information on ever use of tetracycline was asked via questionnaire. Diagnoses of melanoma and SCC were pathologically confirmed.

Results:

Tetracycline use was associated with a modestly increased risk of BCC (n_case=36 377), with a pooled hazard ratio (HR) of 1.11 (95% confidence interval (CI)=1.02–1.21, P-trend=0.05 by duration of use). Tetracycline use was not significantly associated with melanoma (n_case=1831, HR=1.09, 95% CI=0.94–1.27) or SCC (n_case=3332, HR=1.04, 95% CI=0.91–1.18) risk overall. However, we observed positive interactions between tetracycline use and adulthood UV exposure on SCC risk (P-interaction=0.05).

Conclusion:

Tetracycline use was associated with a modestly increased risk of BCC, but was not associated with melanoma or SCC.

Acne in late adolescence is not associated with a raised risk of subsequent malignant melanoma among men

BACKGROUND

To evaluate the association of acne in late adolescence with the risk for subsequent malignant melanoma (MM) in men.

METHODS

Swedish register-based cohort study of 242,096 males born between 1952 and 1956, who took part in compulsory assessments for Swedish military conscription in late adolescence between 1969 and 1975, with subsequent diagnoses of MM (n=1,058) up to December 31, 2009. Covariates included measures of childhood circumstances and information from adolescence on presence of acne, physical fitness, cognitive function, body mass index (BMI), and a summary of diagnoses. Cox regression was used for the analysis.

RESULTS

In total 1,058 men were diagnosed with MM. Acne was not associated with subsequent MM, with an adjusted hazard ratio (and 95% confidence interval) of 0.95 (0.61 to 1.49). Men with parents who were agricultural workers, and men who lived in northern Sweden, had lower physical fitness, or lower cognitive function had a lower risk of MM. Overweight and obesity was associated with a raised risk, with an adjusted hazard ratio of 1.39 (1.14, 1.71).

CONCLUSIONS

Acne in late adolescence is unlikely to represent a raised risk for subsequent MM in men. Overweight or obesity was identified as a raised risk for MM, possibly due to the associated increased skin surface area.

The Generation R Study: design and cohort update 2017

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. This multidisciplinary study focuses on several health outcomes including behaviour and cognition, body composition, eye development, growth, hearing, heart and vascular development, infectious disease and immunity, oral health and facial growth, respiratory health, allergy and skin disorders of children and their parents. Main exposures of interest include environmental, endocrine, genomic (genetic, epigenetic, microbiome), lifestyle related, nutritional and socio-demographic determinants. In total, 9778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. Response at baseline was 61%, and general follow-up rates until the age of 10 years were around 80%. Data collection in children and their parents includes questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, lung function, Magnetic Resonance Imaging and biological sampling. Genome and epigenome wide association screens are available. Eventually, results from the Generation R Study contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

The Generation R Study: design and cohort update 2017

The Generation R Study is a population-based prospective cohort study from fetal life until adulthood. The study is designed to identify early environmental and genetic causes and causal pathways leading to normal and abnormal growth, development and health from fetal life, childhood and young adulthood. This multidisciplinary study focuses on several health outcomes including behaviour and cognition, body composition, eye development, growth, hearing, heart and vascular development, infectious disease and immunity, oral health and facial growth, respiratory health, allergy and skin disorders of children and their parents. Main exposures of interest include environmental, endocrine, genomic (genetic, epigenetic, microbiome), lifestyle related, nutritional and socio-demographic determinants. In total, 9778 mothers with a delivery date from April 2002 until January 2006 were enrolled in the study. Response at baseline was 61%, and general follow-up rates until the age of 10 years were around 80%. Data collection in children and their parents includes questionnaires, interviews, detailed physical and ultrasound examinations, behavioural observations, lung function, Magnetic Resonance Imaging and biological sampling. Genome and epigenome wide association screens are available. Eventually, results from the Generation R Study contribute to the development of strategies for optimizing health and healthcare for pregnant women and children.

Male pattern baldness and risk of incident skin cancer in a cohort of men

We examined the association between male-pattern baldness and risk of incident skin cancer, including invasive melanoma, invasive squamous cell carcinoma (SCC), and basal cell carcinoma (BCC) in a prospective analysis, based on 36,032 participants from the Health Professionals' Follow-up Study. In 1992, participants reported their status of male-pattern baldness at age 45 years by choosing from five crown-view pictograms based on Norwood's classification. Diagnosis of skin cancers was reported biennially and information on melanoma and SCC was pathologically confirmed. We identified 327 melanoma cases, 1324 SCC cases, and 8438 BCC cases during the follow-up. Male-pattern baldness was not significantly associated with risk of incident melanoma, but was significantly associated with increased risk of SCC and BCC. The multivariate-adjusted hazard ratio (HR) (95% confidence interval, CI) for the highest category of baldness (frontal plus severe vertex baldness) was 1.33 (1.06-1.68) for SCC (p_trend  = 0.001) and 1.23 (1.12-1.35) for BCC (p_trend  < 0.0001), compared with no baldness. Analyses by body sites found significant associations between frontal plus moderate to severe vertex baldness and risk of melanoma (HR = 1.83, 95% CI: 1.01-3.34) and SCC (HR = 1.30, 95% CI: 1.02-1.66) at head and neck. The associations were particularly stronger for scalp melanoma (HR = 7.15, 95% CI: 1.29-39.42) and scalp SCC (HR = 7.09, 95% CI: 3.84-13.08), but not for non-scalp head and neck sites. Information on body sites was not available for BCC. In conclusion, male pattern baldness may be associated with increased risk of skin cancer, but the associations may only exist for those occurring at head and neck, particularly at scalp.

Rosacea, Use of Tetracycline, and Risk of Incident Inflammatory Bowel Disease in Women

BACKGROUND & AIMS

Rosacea is an inflammatory skin disease. Case reports have shown rosacea as a comorbidity of inflammatory bowel disease (IBD), but no epidemiologic studies have examined rosacea and risk of subsequent IBD. The association between tetracycline use and risk of IBD was assessed, but this study produced limited findings. We examined the association between rosacea, use of tetracycline, and risk of incident Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We analyzed data from 96,314 participants in the Nurses' Health Study II (1991-2011). Information on IBD was confirmed by medical review. Participants were asked in 2005 about their lifetime histories of clinician-diagnosed rosacea and year of diagnosis. Information on ever use of tetracycline was collected in 1993.

RESULTS

During 1,856,587 person-years (1991-2011), we identified 149 cases of CD and 215 cases of UC. Rosacea was not associated with risk of UC. In contrast, rosacea was significantly associated with increased risk of subsequent CD (hazard ratio [HR], 2.20; 95% confidence interval [CI], 1.15-4.18), which appeared particularly stronger for a longer duration after a diagnosis of rosacea (Ptrend = .01). Tetracycline use was associated with increased risk of CD (HR, 1.56; 95% CI, 1.09-2.24) and UC (HR, 1.34; 95% CI, 1.00-1.80); there was a trend toward increased risk with increased duration of use (both Ptrend < .05) (1993-2011).

CONCLUSIONS

On the basis of an analysis of data from the Nurses' Health Study II, ever use of tetracycline at baseline is associated with an increased risk of CD and UC. Personal history of rosacea is associated with an increased risk of only CD.

Linking diet to acne metabolomics, inflammation, and comedogenesis: an update

Acne vulgaris, an epidemic inflammatory skin disease of adolescence, is closely related to Western diet. Three major food classes that promote acne are: 1) hyperglycemic carbohydrates, 2) milk and dairy products, 3) saturated fats including trans-fats and deficient ω-3 polyunsaturated fatty acids (PUFAs). Diet-induced insulin/insulin-like growth factor (IGF-1)-signaling is superimposed on elevated IGF-1 levels during puberty, thereby unmasking the impact of aberrant nutrigenomics on sebaceous gland homeostasis. Western diet provides abundant branched-chain amino acids (BCAAs), glutamine, and palmitic acid. Insulin and IGF-1 suppress the activity of the metabolic transcription factor forkhead box O1 (FoxO1). Insulin, IGF-1, BCAAs, glutamine, and palmitate activate the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), the key regulator of anabolism and lipogenesis. FoxO1 is a negative coregulator of androgen receptor, peroxisome proliferator-activated receptor-γ (PPARγ), liver X receptor-α, and sterol response element binding protein-1c (SREBP-1c), crucial transcription factors of sebaceous lipogenesis. mTORC1 stimulates the expression of PPARγ and SREBP-1c, promoting sebum production. SREBP-1c upregulates stearoyl-CoA- and Δ6-desaturase, enhancing the proportion of monounsaturated fatty acids in sebum triglycerides. Diet-mediated aberrations in sebum quantity (hyperseborrhea) and composition (dysseborrhea) promote Propionibacterium acnes overgrowth and biofilm formation with overexpression of the virulence factor triglyceride lipase increasing follicular levels of free palmitate and oleate. Free palmitate functions as a "danger signal," stimulating toll-like receptor-2-mediated inflammasome activation with interleukin-1β release, Th17 differentiation, and interleukin-17-mediated keratinocyte proliferation. Oleate stimulates P. acnes adhesion, keratinocyte proliferation, and comedogenesis via interleukin-1α release. Thus, diet-induced metabolomic alterations promote the visible sebofollicular inflammasomopathy acne vulgaris. Nutrition therapy of acne has to increase FoxO1 and to attenuate mTORC1/SREBP-1c signaling. Patients should balance total calorie uptake and restrict refined carbohydrates, milk, dairy protein supplements, saturated fats, and trans-fats. A paleolithic-like diet enriched in vegetables and fish is recommended. Plant-derived mTORC1 inhibitors and ω-3-PUFAs are promising dietary supplements supporting nutrition therapy of acne vulgaris.