The association between obesity and urinary tract infection

Obesity promotes urinary tract infection by disrupting urothelial immune defenses

Obesity is a significant public health concern that is associated with numerous health risks. Infections are a major complication of obesity, but the mechanisms responsible for increased infection risk are poorly defined. Here, we use a diet induced obesity mouse model and investigate how obesity impacts urinary tract infection (UTI) susceptibility and bladder immune defenses. Our results show that high-fat diet fed female and male mice exhibit increased susceptibility to uropathogenic E. coli (UPEC) following experimental UTI. Transcriptomic analysis of bladder urothelial cells shows that obesity alters gene expression in a sex-specific manner, with distinct differentially expressed genes in male and female mice, but shared activation of focal adhesion and extracellular matrix signaling. Western blot and immunostaining confirm activation of focal adhesion kinase, a central component of the focal adhesion pathway, in the bladders of obese female and male mice. Mechanistically, experiments using primary human urothelial cells demonstrate that focal adhesion kinase overexpression promotes UPEC invasion. These findings demonstrate that obesity enhances UTI susceptibility by activating focal adhesion kinase and promoting bacterial invasion of the urothelium. Together, they explain how obesity promotes UTI vulnerability and identify modifiable targets for managing obesity-associated UTI.

Significance Statement

Obesity is associated with an increased risk of urinary tract infections (UTIs), but the underlying mechanisms promoting infection susceptibility remain poorly understood. Here, we show that diet-induced obesity drives sex-specific changes in bladder urothelial gene expression, including distinct immune responses in male and female mice. Despite these differences, both sexes exhibit activation of focal adhesion kinase (FAK). FAK overexpression promotes bacterial invasion into human bladder cells. These findings provide a mechanistic explanation for obesity-associated UTI susceptibility and suggest that targeting FAK signaling could offer a therapeutic strategy to prevent UTIs, with implications for personalized interventions in obesity.

Epidemiology of urinary tract infection among community-living seniors aged 50 plus: Population estimates and risk factors

BACKGROUND

Urinary tract infection (UTI) is common in all ages but risk factors among adults 50 and older are not well studied. One unexplored potential risk factor is constipation, a known UTI risk factor among children.

METHODS

A web interview was administered October 12-16, 2023 to 1074 U.S. adults aged 50 and older participating in a probability-based panel representative of the U.S. household population age 50 or older. The primary study outcome was self-reported healthcare provider diagnosed and treated UTI in the previous 12 months. All results were weighted to represent the U.S. household population.

RESULTS

The 12-month UTI incidence was 19.8 % among women and 6.4 % among men. 32 % of the population reported being constipated sometimes, frequently or always. After adjusting for age, gender, having a body mass index > 30 and an overnight hospital stay in the previous 12 months, those reporting sometimes being constipated were 3.69 times, and those often or always constipated were 5.48 times more likely than those never constipated to have a UTI in the previous 12 months.

DISCUSSION

This is the first report of an association between UTI and constipation among older adults. Reducing constipation might reduce UTI incidence among older women and men.

Causal Relationship Between Intelligence, Noncognitive Education, Cognition and Urinary Tract or Kidney Infection: A Mendelian Randomization Study

Background

The occurrence of urinary tract or kidney infection is correlated with intelligence, noncognitive education and cognition, but the causal relationship between them remains uncertain, and which risk factors mediate this causal relationship remains unknown.

Methods

The intelligence (n=269,867), noncognitive education (n=510,795) and cognition data (n=257,700) were obtained from genome-wide association studies (GWAS) conducted in individuals of European ethnicities. The genetic associations between these factors and urinary tract or kidney infection (UK Biobank, n=397,867) were analyzed using linkage disequilibrium score regression. We employed a two-sample univariate and multivariate Mendelian randomization to evaluate the causal relationship, and utilized a two-step Mendelian randomization to examine the involvement of 28 potential mediators and their respective mediating proportions.

Results

The genetic correlation coefficients of intelligence, noncognitive education, cognition, and urinary tract or kidney infection were -0.338, -0.218, and -0.330. The Mendelian randomization using the inverse variance weighted method revealed each 1-SD increase in intelligence, the risk of infection decreased by 15.9%, while after adjusting for noncognitive education, the risk decreased by 20%. For each 1-SD increase in noncognitive education, the risk of infection decreased by 8%, which further reduced to 7.1% after adjusting for intelligence and to 6.7% after adjusting for cognition. For each 1-SD increase in cognition, the risk of infection decreased by 10.8%, increasing to 11.9% after adjusting for noncognitive education. The effects of intelligence and cognition are interdependent. 2 out of 28 potential mediating factors exhibited significant mediation effects in the causal relationship between noncognitive education and urinary tract or kidney infection, with body mass index accounting for 12.1% of the mediation effect and smoking initiation accounting for 14.7%.

Conclusion

Enhancing intelligence, noncognitive education, and cognition can mitigate the susceptibility to urinary tract or kidney infection. Noncognitive education exhibited independent effect, while body mass index and smoking initiation assuming a mediating role.

A Genome-wide Association Study of Susceptibility to Upper Urinary Tract Infections

BACKGROUND

Our goal was to identify genetic and modifiable risk factors for upper urinary tract infections (UTIs).

METHODS

We used data from UK Biobank, the Trøndelag Health Study, and the Michigan Genomics Initiative to conduct genome-wide association studies and sex-stratified analyses on upper UTI. Mendelian randomization (MR) analyses were conducted to examine potential causal relationships between cardiometabolic risk factors and upper UTIs.

RESULTS

One genome-wide significant (P ≤ 5E-08) locus was associated with the susceptibility to upper UTI, located near TSN in the female-only analysis. Additionally, we identified suggestive (P ≤ 5E-06) loci near DNAI3 for females, SCAMP1-AS1 for males, and near TSN, LINC00603, and HLA-DQA2 for both sexes. In MR analyses, higher genetically predicted lifetime smoking scores were associated with an increased risk of developing upper UTI for females and both sexes (odds ratio [OR], 4.84, P = 4.50E-06 and OR, 2.79, P = 3.02E-05, respectively).

CONCLUSIONS

We found that genetic variants near TSN was associated with the risk of upper UTIs among females. In addition, we found several genetic loci with suggestive associations with the risk of upper UTIs. Finally, MR analyses found smoking to be a potential causal risk factor for upper UTIs.

Risk Factors for Recurrent Urinary Tract Infections Among Women in a Large Integrated Health Care Organization in the United States

BACKGROUND

Urinary tract infections (UTIs) occur commonly and often recur. However, recent data on the epidemiology of recurrent UTI (rUTI) are scarce.

METHODS

Between 1 January 2016 and 31 December 2020, index uncomplicated UTIs (uUTIs) from office, emergency department, hospital, and virtual care settings were identified from the electronic health records of women at Kaiser Permanente Southern California. We defined rUTI as ≥3 UTIs within 365 days or ≥2 UTIs within 180 days. We determined the proportion of women with cystitis index uUTI who had rUTI, and we examined factors associated with rUTIs using modified multivariable Poisson regression.

RESULTS

Among 374 171 women with cystitis index uUTI, 54 318 (14.5%) had rUTI. A higher proportion of women with rUTI vs those without rUTI were aged 18 to 27 or ≥78 years at index uUTI (19.7% vs 18.7% and 9.0% vs 6.0%, respectively), were immunocompromised, or had a positive urine culture result at index uUTI. In multivariable analyses, characteristics associated with rUTI included younger or older age (48-57 vs 18-27 years: adjusted risk ratio [aRR], 0.83 [95% CI, .80-.85]; ≥78 vs 18-27 years: aRR, 1.07 [95% CI, 1.03-1.11]), Charlson Comorbidity Index (≥3 vs 0: aRR, 1.12 [95% CI, 1.08-1.17]), and diabetes mellitus (aRR, 1.07 [95% CI, 1.04-1.10]). More frequent prior-year outpatient and emergency department encounters, oral antibiotic and oral contraceptive prescriptions, positive culture result at index uUTI, and antibiotic-resistant organisms were also associated with increased risk of rUTI.

CONCLUSIONS

The high risk of rUTI among women with cystitis is concerning, especially given previous reports of increasing UTI incidence. Current assessment of the epidemiology of rUTI may guide the development of preventive interventions against UTI.

Risk factors for urinary tract infection in geriatric hip fracture patients: a systematic review and meta-analysis

Background

Urinary tract infection (UTI) is a prevalent and consequential complication in hip fracture patients, leading to significant disability and heightened healthcare expenditures. Consequently, there is a critical need for a comprehensive systematic review to identify risk factors and establish early and effective preventive measures.

Methods

A comprehensive search was performed across the PubMed, Cochrane, Embase, Web of Science, and Scopus databases (up to August 31, 2023). Article screening, data extraction, and quality assessment were independently completed by two reviewers.

Results

Forty-four studies were eligible for inclusion, yielding an overall incidence rate of 11% (95% CI: 8%-14%). Our pooled analysis revealed 18 significant risk factors, including being female (OR = 2.23, 95% CI: 1.89-2.63), advanced age (MD = 1.35, 95% CI: 0.04-2.66), obesity (OR = 1.21, 95% CI: 1.11-1.31), catheterization (OR = 3.8, 95% CI: 2.29-6.32), blood transfusion (OR = 1.39, 95% CI: 1.21-1.58), American Society of Anesthesiologists ≥III (OR = 1.28, 95% CI: 1.18-1.40), general anesthesia (OR = 1.26, 95% CI: 1.11-1.43), intertrochanteric fracture (OR = 1.25, 95% CI: 1.01-1.54), hemiarthroplasty (OR = 1.43, 95% CI: 1.19-1.69), prolonged length of hospital stay (MD = 1.44, 95% CI: 0.66-2.23), delirium (OR = 2.66, 95% CI: 2.05-3.47), dementia (OR = 1.82, 95% CI: 1.62-2.06), Parkinson's disease (OR = 1.53, 95% CI: 1.46-1.61), diabetes (OR = 1.27, 95% CI: 1.13-1.43), hypertension (OR = 1.14, 95% CI: 1.03-1.26), congestive heart failure (OR = 1.35, 95% CI: 1.10-1.66), history of sepsis (OR = 7.13, 95% CI: 5.51-9.22), and chronic steroid use (OR = 1.29, 95% CI: 1.06-1.57).

Conclusion

Our study identifies numerous risk factors strongly associated with UTI, offering compelling evidence and actionable strategies for improving clinical prediction, enabling early intervention, and facilitating targeted UTI management.

Systematic review registration

identifier [CRD42023459600], https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=459600.

Propolis as an adjunctive therapy for treatment of uncomplicated cystitis in women: A randomized double-blind placebo-controlled trial

The current research is designed to investigate the effect of propolis supplementation on the clinical manifestations in women suffering from uncomplicated cystitis. In this randomized double-blind, placebo-controlled trial, 120 women with uncomplicated cystitis were selected and randomly assigned into two groups to receive two 500 mg capsules of propolis or placebo daily for 7 days along with ciprofloxacin (250 mg). Clinical symptoms including hematuria, urinary frequency, dysuria, suprapubic pain, and urgency, as well as bacteriuria, were assessed before and after the intervention. After supplementation, participants in the intervention group had significantly fewer days of urinary frequency (p < 0.001), dysuria (p = 0.005), and urgency (p = 0.03). However, there was no significant difference between the two groups regarding hematuria and suprapubic pain (p > 0.05). Furthermore, the severity of bacteriuria decreased significantly in both groups. In conclusion, it seems that propolis supplementation in women with uncomplicated cystitis could improve urinary frequency, dysuria, and urgency. However, further clinical trials should be conducted to fully understand the effects of propolis in women suffering from uncomplicated cystitis.

The Role of Non-Alcoholic Fatty Liver Disease in Infections

Non-alcoholic fatty liver disease (NAFLD) is the most prevalent chronic liver disease, affecting one third of the Western population. The hallmark of the disease is excessive storage of fat in the liver. Most commonly, it is caused by metabolic syndrome (or one of its components). Even though the development of NAFLD has multiple effects on the human organism resulting in systemic chronic low-grade inflammation, this review is focused on NAFLD as a risk factor for the onset, progression, and outcomes of infectious diseases. The correlation between NAFLD and infections is still unclear. Multiple factors (obesity, chronic inflammation, altered immune system function, insulin resistance, altered intestinal microbiota, etc.) have been proposed to play a role in the development and progression of infections in people with NAFLD, although the exact mechanism and the interplay of mentioned factors is still mostly hypothesized. In this article we review only the selection of well-researched topics on NAFLD and infectious diseases (bacterial pneumonia, COVID, H. pylori, urinary tract infections, C. difficile, bacteremia, hepatitis B, hepatitis C, HIV, and periodontitis).

Systematic Review of Literature Examining Bacterial Urinary Tract Infections in Diabetes

This systematic review addresses the central research question, "what is known from the published, peer-reviewed literature about the impact of diabetes on the risk of bacterial urinary tract infections (UTI)?" We examine the results from laboratory studies where researchers have successfully adapted mouse models of diabetes to study the pathophysiology of ascending UTI. These studies have identified molecular and cellular effectors shaping immune defenses against infection of the diabetic urinary tract. In addition, we present evidence from clinical studies that in addition to diabetes, female gender, increased age, and diabetes-associated hyperglycemia, glycosuria, and immune impairment are important risk factors which further increase the risk of UTI in diabetic individuals. Clinical studies also show that the uropathogenic genera causing UTI are largely similar between diabetic and nondiabetic individuals, although diabetes significantly increases risk of UTI by drug-resistant uropathogenic bacteria.

Impact of Bariatric Surgery on Unplanned Hospital Admissions for Infection

Purpose

Both obesity and type 2 diabetes are associated with an increased risk of skin and soft tissue (SSTI), urinary tract, and lower respiratory tract infections but it is not clear whether the incidence of such infections is reduced after bariatric surgery.

Materials and Methods

In people accepted onto our publicly funded bariatric program, we recorded unplanned admissions to public hospitals over a median follow-up of 4.5 years in those successfully undergoing surgery and in those who withdrew from the program. Rates of admission for the composite outcome (SSTI, urinary tract, or lower respiratory infection) were compared.

Results

Of 774 people accepted onto the program, 49% underwent surgery. Infections accounted for 27% of unplanned admissions in those not completing surgery and 13% of those who underwent surgery (p < 0.001). The rate of admission was 60% lower in people who underwent surgery than those who did not: 4.3 vs 12.2 per 100 patient-years (P < 0.002), a difference maintained across 8 years’ follow-up. The impact of surgery was independent of enrolment age, BMI, or diabetes and smoking status. Of the three types of infection in the composite outcome, SSTI were the most prevalent and showed the greatest reduction (p < 0.0001). The median day stay for infection was 0.5 day less in those who underwent surgery (p < 0.01).

Conclusions

Hospitalization for these three infectious diseases in people undergoing bariatric surgery was lower than that in people enrolled in the bariatric program but not completing surgery. The effect was greatest for SSTI, and sustained to at least 8 years.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s11695-022-05975-4.

Association between body mass index and urinary tract infection: a systematic review and meta-analysis of observational cohort studies

BACKGROUND AND OBJECTIVE

Very few studies have investigated the relationship between body mass index (BMI) and risk of urinary tract infection (UTI), and conclusions from these available studies have been inconsistent. To resolve this inconsistency, we performed a systematic review and meta-analysis to precisely examine the association between BMI and UTI.

METHODS

This meta-analysis was performed based on the PRISMA recommendations. PubMed, Web of Science, Scopus, Embase, and Google Scholar databases were searched for all published observational studies that reported the risk of UTI based on BMI categories up to March 2020.

RESULTS

Fourteen (n = 14) articles comprising 19 studies in different populations met our inclusion criteria. The overall analysis showed a significant increased risk of UTI in subjects affected by obesity vs. individuals without obesity (RR = 1.45; 95% CI: 1.28 - 1.63; I² = 94%), and a non-significant increased risk of UTI in subjects who were overweight (RR = 1.03; 95% CI: 0.98 - 1.10; I² = 49.6%) and underweight (RR = 0.99; 95% CI: 0.81 - 21; I² = 0.0%) when compared to subjects who had normal weight. In the stratified analysis, we showed that obesity increased the risk of UTI in females (RR = 1.63; 95% CI: 1.38 - 1.93) and in subjects below 60 years old (RR = 1.53; 95% CI: 1.33 - 1.75).

CONCLUSION

This systematic review and meta-analysis recognized a significant relationship between BMI and incidence of UTI in obese vs. non-obese subjects, as well as in females and in individuals below 60 years old.

The impact of obesity on immune response to infection: Plausible mechanisms and outcomes

Emerging data suggest an association between obesity and infectious diseases. Although the mechanisms underlying this link are not well established, a number of potential factors may be involved. Indeed, the obesity-related vulnerability to infectious diseases could be due to chronic low-grade inflammation, hyperglycemia, hyperinsulinemia, and hyperleptinemia, which lead to a weakening of both the innate and adaptive immune responses. In addition, obesity results in anatomical-functional changes by the mechanical obstacle of excessive adipose tissue that blunt the respiratory mechanisms and predisposing to respiratory infections. Subjects with obesity are also at risk of skin folds and sweat more profusely due to the thick layers of subcutaneous fat, favoring the proliferation of microorganisms and slowing the repair of wounds down. All these factors make subjects with obesity more prone to develop nosocomial infections, surgical site, skin and soft tissue infections, bacteremia, urinary tract infections, and mycosis. Furthermore, infections in subjects with obesity have a worse prognosis, frequently prolonging hospitalization time as demonstrated for several flu viruses and recently for COVID-19. Thus, the aim of this manuscript is to provide an overview of the current clinical evidence on the associations between obesity and infectious diseases highlighting physio pathological insights involved in this link.

Obesity, metabolic health, and urological disorders in adults: a nationwide population-based study

We evaluate the risks of various urological disorders that require treatments according to obesity and metabolic health status using a nationwide dataset of the Korean population. 3,969,788 patients who had undergone health examinations were enrolled. Participants were classified as “obese” (O) or “non-obese” (NO) using a BMI cut-off of 25 kg/m2. People who developed ≥ 1 metabolic disease component in the index year were considered “metabolically unhealthy” (MU), while those with none were considered “metabolically healthy” (MH). There were classified into the MHNO, MUNO, MHO, and MUO group. In BPH, chronic renal disease, neurogenic bladder, any medication related to voiding dysfunction, alpha-blocker, and antidiuretics, age and gender-adjusted hazard ratio (HR) was highest in MUO, but higher in MUNO than in MHO. In stress incontinence, prostate surgery, and 5alpha-reductase, HR increased in the order of MUNO, MHO, and MUO. In prostatitis, anti-incontinence surgery, and cystocele repair, HR was higher in MHO than MUNO and MUO. In cystitis, cystostomy, and anticholinergics, HR was higher in MUNO and MUO than MHO. In conclusion, obesity and metabolic health were individually or collaboratively involved in urological disorders related to voiding dysfunction. Metabolic healthy obesity needs to be distinguished in the diagnosis and treatment of urological disorders.

NAFLD and Infection, a Nuanced Relationship

The prevalence of nonalcoholic fatty liver disease (NAFLD) has increased significantly over the last few decades mirroring the increase in obesity and type II diabetes mellitus. NAFLD has become one of the most common indications for liver transplantation. The deleterious effects of NAFLD are not isolated to the liver only, for it has been recognized as a systemic disease affecting multiple organs through protracted low-grade inflammation mediated by the metabolic activity of excessive fat tissue. Extrahepatic manifestations of NAFLD such as cardiovascular disease, polycystic ovarian syndrome, chronic kidney disease, and hypothyroidism have been well described in the literature. In recent years, it has become evident that patients suffering from NAFLD might be at higher risk of developing various infections. The proposed mechanism for this association includes links through hyperglycemia, insulin resistance, alterations in innate immunity, obesity, and vitamin D deficiency. Additionally, a risk independent of these factors mediated by alterations in gut microbiota might contribute to a higher burden of infections in these individuals. In this narrative review, we synthetize current knowledge on several infections including urinary tract infection, pneumonia, Helicobacter pylori, coronavirus disease 2019, and Clostridioides difficile as they relate to NAFLD. Additionally, we explore NAFLD's association with hidradenitis suppurativa.

Impact of Obesity on Urinary Tract Infections in Korean Adults: Secondary Data Analysis Using Community-Based Cohort Study

PURPOSE

This study investigated the incidence of urinary tract infection (UTI) in community-dwelling adults and identified the association between obesity and UTI.

METHODS

The participants were 4,926 adults aged over 40 years who had no UTIs at the baseline survey of the Korean Genome Epidemiology Study. Obesity was defined according to the cirtieria of Korean Society for the Study of Obesity using body mass index (BMI) data. UTI was defined as those who had self-reported UTI or had either nitrite, or both leukocytes and blood in the urine dipstick test. Hazard ratio (HR) and 95% confidence interval (CI) were calculated using a multivariate Cox proportional hazards regression analysis to identify the association between the obesity and UTI.

RESULTS

The incidence proportion of UTI was 5.1%, and the incidence density per 1,000 person-years was 25.5. After controlling general characteristics, people with BMI ≥30.0 kg/m² remained 1.66 times (HR = 1.66, 95% CI = 1.06~2.60; p < .05) more likely to have UTI than those with normal weight. This trend was also present in men or people aged ≥ 60 years. Among women aged ≥ 60 years, people with BMI ≥ 30.0 kg/m² were 1.98 times (HR = 1.98, 95% CI = 1.01~3.86; p < .05) more likely to have UTI than those with normal weight.

CONCLUSION

The BMI ≥ 30.0 kg/m² is a risk factor of UTIs in Korean adult men over 40 years and women aged ≥ 60 years. It is necessary to emphasize the importance of obesity management to men or women aged ≥ 60 years, specifically.

The impact of obesity on perioperative complications in patients undergoing anterior lumbar interbody fusion

OBJECTIVE

Anterior approaches to the lumbar spine provide wide exposure that facilitates placement of large grafts with high fusion rates. There are limited data on the effects of obesity on perioperative complications.

METHODS

Data from consecutive patients undergoing anterior lumbar interbody fusion (ALIF) from 2007 to 2016 at a single academic center were analyzed. The primary outcome was any perioperative complication. Complications were divided into those occurring intraoperatively and those occurring postoperatively. Multivariate logistic regression was used to assess the association of obesity and other variables with these complications. An estimation table was used to identify a body mass index (BMI) threshold associated with increased risk of postoperative complication.

RESULTS

A total of 938 patients were identified, and the mean age was 57 years; 511 were females (54.5%). The mean BMI was 28.7 kg/m2, with 354 (37.7%) patients classified as obese (BMI ≥ 30 kg/m2). Forty patients (4.3%) underwent a lateral transthoracic approach, while the remaining 898 (95.7%) underwent a transabdominal retroperitoneal approach. Among patients undergoing transabdominal retroperitoneal ALIF, complication rates were higher for obese patients than for nonobese patients (37.0% vs 28.7%, p = 0.010), a difference that was driven primarily by postoperative complications (36.1% vs 26.0%, p = 0.001) rather than intraoperative complications (3.2% vs 4.3%, p = 0.416). Obese patients had higher rates of ileus (11.7% vs 7.2%, p = 0.020), wound complications (11.4% vs 3.4%, p < 0.001), and urinary tract infections (UTI) (5.0% vs 2.5%, p = 0.049). In a multivariate model, age, obesity, and number of ALIF levels fused were associated with an increased risk of postoperative complication. An estimation table including 19 candidate cut-points, odds ratios, and adjusted p values found a BMI ≥ 31 kg/m2 to have the highest association with postoperative complication (p = 0.012).

CONCLUSIONS

Obesity is associated with increased postoperative complications in ALIF, including ileus, wound complications, and UTI. ALIF is a safe and effective procedure. However, patients with a BMI ≥ 31 kg/m2 should be counseled on their increased risks and warrant careful preoperative medical optimization and close monitoring in the postoperative setting.

Obesity and risk of infections: results from men and women in the Swedish National March Cohort

BACKGROUND

Previous studies have shown an association between body mass index (BMI) and infections, but the literature on type-specific community acquired infections is still limited.

METHODS

We included 39 163 Swedish adults who completed a questionnaire in September 1997 and were followed through record-linkages until December 2016. Information on BMI was self-reported and infections were identified from the Swedish National Patient Register using International Classification of Diseases (ICD), Tenth Revision (ICD-10) codes. We fitted multivariable Cox proportional hazards models for time-to-first-event analysis, and we used extensions of the standard Cox model when repeated events were included.

RESULTS

During a 19-year follow-up 32% of the subjects had at least one infection requiring health care contact, leading to a total of 27 675 events. We found an increased incidence of any infection in obese women [hazard ratio (HR) = 1.22; 95% confidence interval (CI) = 1.12; 1.33] and obese men (HR = 1.25; 95% CI = 1.09; 1.43) compared with normal weight subjects. For specific infections, higher incidences were observed for skin infections in both genders (HR = 1.76; 95% CI = 1.47; 2.12 for obese females and HR = 1.74; 95% CI = 1.33; 2.28 for obese males) and gastrointestinal tract infections (HR = 1.44; 95% CI = 1.19; 1.75), urinary tract infections (HR = 1.30; 95% CI = 1.08; 1.55) and sepsis (HR = 2.09; 95% CI = 1.46; 2.99) in obese females. When accounting for repeated events, estimates similar to the aforementioned ones were found.

CONCLUSIONS

Obesity was associated with an increased risk of infections in both genders. Results from multiple-failure survival analysis were consistent with those from classic Cox models.

Beneficial effect of sugar-sweetened beverages on the risk of urinary tract infections

Urinary tract infections (UTI) are among the most common bacterial infections. Drinking more liquids increases the frequency of urination and it is recommended as part of the prevention and/or management of UTI. The intake of sugar-sweetened beverages (SSB) is associated with obesity, diabetes and metabolic syndrome. However, cola and other SSB increase liquid intake and diuresis and could, thus, affect the risk of UTI and its complications. We hypothesize that intake of cola has a protective effect on UTI and pyelonephritis. Using an animal model of UTI, we have confirmed that dehydration with minimal urine output leads to higher bacterial counts in the kidneys in comparison to control mice (p = 0.01). The intake of SSB increased liquid intake and thus also diuresis and decreased renal bacterial counts as a marker of induced pyelonephritis (p = 0.036). The preliminary results show that dehydration is a risk factor for UTI and that higher diuresis induced by drinking SSB might be protective against pyelonephritis. The underlying mechanisms could include increased voiding frequency but potentially also active compounds in cola such as caffeine. These findings might have implications for the management of individuals at high risk of UTI. Further studies should verify the hypothesis and evaluate the practical relevance of this concept.

Adult Neurogenic Lower Urinary Tract Dysfunction and Intermittent Catheterisation in a Community Setting: Risk Factors Model for Urinary Tract Infections

A risk factor model for urinary tract infections in patients with adult neurogenic lower urinary tract dysfunction performing clean intermittent catheterisation was developed; it consists of four domains, namely, (1) general (systemic) conditions in the patient, (2) individual urinary tract conditions in the patient, (3) routine aspects related to the patient, and (4) factors related to intermittent catheters per se. The conceptual model primarily concerns patients with spinal cord injury, spina bifida, multiple sclerosis, or cauda equina where intermittent catheterisation is a normal part of the bladder management. On basis of several literature searches and author consensus in case of lacking evidence, the model intends to provide an overview of the risk factors involved in urinary tract infections, with specific emphasis to describe those that in daily practice can be handled and modified by the clinician and so come to the benefit of the individual catheter user in terms of fewer urinary tract infections.

Reuniting overnutrition and undernutrition, macronutrients, and micronutrients

Over-nutrition and its late consequences are a dominant theme in medicine today. In addition to the health hazards brought on by over-nutrition, the medical community has recently accumulated a roster of health benefits with obesity, grouped under "obesity paradox." Throughout the world and throughout history until the 20^th century, under-nutrition was a dominant evolutionary force. Under-nutrition brings with it a mix of benefits and detriments that are opposite to and continuous with those of over-nutrition. This continuum yields J-shaped or U-shaped curves relating body mass index to mortality. The overweight have an elevated risk of dying in middle age of degenerative diseases while the underweight are at increased risk of premature death from infectious conditions. Micronutrient deficiencies, major concerns of nutritional science in the 20^th century, are being neglected. This "hidden hunger" is now surprisingly prevalent in all weight groups, even among the overweight. Because micronutrient replacement is safe, inexpensive, and predictably effective, it is now an exceptionally attractive target for therapy across the spectrum of weight and age. Nutrition-related conditions worthy of special attention from caregivers include excess vitamin A, excess vitamin D, and deficiency of magnesium.

Obesity and risk of urinary tract infection in young children presenting with fever

Obesity may increase the risk of infection, but the association between obesity and febrile urinary tract infection (fUTI) is controversial. Although the prevalence of infant and childhood obesity has been increasing worldwide, the results of previous investigations on the association with urinary tract infection (UTI) are conflicting. The purpose of this study was to evaluate the relationship between overweight and obesity and UTI in febrile children.The study reviewed medical records of a consecutive series of 472 children <2 years of age presenting with fever ≥ 38°C were retrospectively evaluated and stratified by the presence or absence of a UTI. The proportions of underweight, healthy weight, overweight, and obese children in the 2 groups were compared following calculation of individual weight-for-length percentiles. The effect of obesity on UTI risk was evaluated, and odds ratios (ORs) were calculated.A total of 212 patients with and 260 controls without UTI were included. There were more overweight and obese children with (71/212, 33.5%) than without UTIs (45/260, 17.3%; P < .001). The OR of UTI in overweight relative to healthy-weight children was 1.92 [95% confidence interval (95% CI):1.15-3.21]. The OR of UTI in obese relative to healthy weight children was 2.46 (95% CI: 1.54-3.93).Compared with previous studies that made comparison between UTI and healthy children, this is the first study to demonstrate an association of obesity and fUTI in febrile children <2 years of age. In this series of pediatric patients, obesity was strongly associated with the presence of fUTI and obese children had a higher risk of developing an UTI than nonobese children.The incidence of UTI was higher in young, overweight, and obese children presenting with fever than in normal-weight, febrile children. Control of excess body weight should be considered as early as possible. Urinalysis should be considered for obese children <2 years of age who present with fever, especially those with mild respiratory or gastrointestinal symptoms.

Prevalence and risk factors for urinary tract infection following stress urinary incontinence surgery with two midurethral sling procedures

OBJECTIVE

To compare prevalence and risk factors for urinary tract infection (UTI) following midurethral sling surgery with either the GYNECARE ABBREVO Continence System (Ethicon, Somerville, NJ, USA) or a standard transobturator.

METHODS

A retrospective cohort study was conducted among women who underwent midurethral sling surgery to treat stress urinary incontinence at a single tertiary hospital in Israel between January 1, 2014, and August 11, 2015. Data were retrieved from medical records. The diagnosis of UTI was based on a positive urine culture result.

RESULTS

Of 178 patients included, 30 (16.9%) underwent the ABBREVO procedure and 148 (83.1%) underwent the standard transobturator procedure. The mean ± SD BMI at the time of surgery was 28.1 ± 4.5 for the standard transobturator procedures and 30.7 ± 15.2 for the ABBREVO procedures. Women who underwent the ABBREVO procedure had an increased duration of hospitalization (P=0.004), and higher rates of concomitant anterior colporrhaphy procedures (P=0.009) and concomitant hysterectomy (P=0.009). Only 38 (21.3%) women developed UTIs within 12 months of surgery (seven in the ABBREVO procedure group and 31 in the standard transobturator procedure group). No statistically significant between-group differences were found for the risk of UTI or for urinary tract adverse events, such as recurrent UTI and the need for rehospitalization.

CONCLUSIONS

The two procedures were comparable in terms of prevalence and risk factors for UTI during the postoperative period.

Intrarenal Injection of Escherichia coli in a Rat Model of Pyelonephritis

Pyelonephritis is a bacterial infection of the kidney and is most commonly caused by Escherichia coli. Recurrent infections can cause significant renal inflammation and fibrosis ultimately resulting in declining kidney function. Before improved clinical management and prevention of pyelonephritis can be instituted, a reliable animal model must be established in order to study the mechanisms of progression, recurrence, and therapeutic efficacy. The transurethral infection model closely mimics human pyelonephritis but exhibits considerable variation due to its reliance on urethral reflux to transport the bacteria to the kidney. Herein, a detailed surgical protocol for performing bacterial injections into the rat renal pelvis is provided and confirmed by non-invasive Magnetic Resonance Imaging (MRI). Using this protocol, animals receive direct exposure to a desired concentration of E. coli bacteria and can fully recover from the surgical procedure with adequate post-operative care. This facilitates subsequent longitudinal MRI assessments of the experimental animal models for comparison with saline (sham) controls. Using this direct delivery approach, the severity of infection is controllable and applicable for mechanistic studies of progression as well as development of novel treatment strategies.

Are there any predictors of pyonephrosis in patients with renal calculus disease?

The objective of the study is to identify factors predicting development of pyonephrosis in patients of renal calculus disease (RCD), as this knowledge is largely unknown. Patients of RCD without pyonephrosis (Group 1) or with pyonephrosis (Group 2) presenting between December 2013 and November 2015 were evaluated. All patients of RCD who had undergone either percutaneous nephrostomy (PCN) or surgical management (percutaneous nephrolithotomy/pyelolithotomy/nephrectomy) were included. Patients treated conservatively, by extracorporeal shock-wave lithotripsy and patients of bilateral RCD were excluded. Data regarding demography, co-morbidities, associated urologic disease, previous intervention, clinical presentation, urinary culture, renal function, grade of hydronephrosis, stone characteristics were collected. 501 patients were included (Group 1: 410; Group 2: 91). Mean age in years (35.02 versus 35.48), sex ratio (2.12:1 versus 2.25:1) and mean body mass index (kg/m²) (22.27 versus 22.15) were similar in both groups. Prevalence of diabetes mellitus (3.41% versus 3.29%, p = 1.000) was similar. Group 2 patients had longer duration of symptoms (5.77 versus 8.96 months, p < 0.0001), associated urological diseases such as ipsilateral PUJO and ureteric calculus (4.63% versus 12.08%, p = 0.0125), moderate/severe-grade hydronephrosis (49.75% versus 92.30%, p < 0.0001), presence of staghorn calculus (20.73% versus 62.63%, p < 0.0001), multiple calculi (48.29% versus 68.13% p = 0.0007) and nonfunctioning kidney (1.70% versus 71.42%, p < 0.0001) as predictors of pyonephrosis. In logistic multivariate analysis, additionally, past history of urological surgery (p = 0.044) was found associated with pyonephrosis. Our study identified some conditions associated with patients of pyonephrosis. To prove their role as risk factors we recommend further studies.

Obesity as a Risk Factor for Urinary Tract Infection in Children

Childhood obesity is a nationwide epidemic with an estimated 16% to 18% of children and adolescents qualifying as obese and another 21% to 24% considered overweight. Obesity has been linked to an increased risk of developing serious infections. Healthcare Cost and Utilization Project-Kids' Inpatient Database 2009 was queried to analyze national trends in patient encounters, specifically those listing patients as comorbid obese and then identified those with urinary tract infection (UTI) as primary or secondary diagnosis. Propensity matching was used to calculate risk for UTI in the inpatient obese pediatric population. A total of 86 638 pediatric hospital admissions were enrolled in the study of which 41 819 included the diagnosis of obesity, and a UTI was diagnosed in 2445 of the cases. In a propensity-matched sample, matched for age, sex, race, and diabetes mellitus, the risk of UTI was increased by 45% in obese females. Obese males did not have a significantly increased risk for UTI.

Body Mass Index and Risk of Infections Among Women in the Danish National Birth Cohort

We investigated the possible association between body mass index (BMI; weight (kg)/height (m)(2)) and hospitalization or treatment for acute infection in a prospective cohort study. We linked 75,001 women enrolled in the Danish National Birth Cohort from 1996 to 2002, who had information on BMI and a broad range of confounders, to data on infectious diseases and use of antimicrobial agents from the National Patient Register and the Danish Prescription Register. Associations were tested using Cox proportional hazards models. During 12 years of follow-up, we observed a U-shaped association between baseline BMI and later hospitalization for 1) any infectious disease and 2) infections of the respiratory tract, whereas a dose-response relationship was seen for skin infections. The most pronounced associations were seen for acute upper respiratory infections at multiple and unspecified sites (underweight (BMI <18.5): hazard ratio (HR) = 4.26, 95% confidence interval (CI): 1.69, 10.7; obesity (BMI ≥30): HR = 3.64, 95% CI: 1.62, 8.18), erysipelas (obesity: HR = 5.19, 95% CI: 3.38, 7.95), and fungal infections (underweight: HR = 3.19, 95% CI: 1.53, 6.66). Slightly greater use of antimicrobials was observed among overweight (BMI 25-<30; HR = 1.08, 95% CI: 1.06, 1.10) and obese (HR = 1.21, 95% CI: 1.17, 1.24) women. Among Danish women, underweight and obesity were associated with increased risk of community-acquired infectious diseases, especially infections of the upper respiratory tract and skin.

Prevalence of asymptomatic urinary tract infections in morbidly obese dogs

Background. Obesity has reached epidemic proportions in dogs and, as in humans, cost of care has increased due to associated comorbidities. In humans, asymptomatic urinary tract infections (UTI) may be more prevalent in the obese. Asymptomatic bacteriuria (AB) is the term used when UTI are asymptomatic. We hypothesized that morbidly obese dogs are similarly more likely to have asymptomatic bacteriuria than lean, overweight, and moderately obese dogs.

Methods. A retrospective study was undertaken to explore a possible association between obesity and asymptomatic bacteriuria. Records from lean, overweight, and obese dogs receiving both a dual energy absorptiometry (DXA) scan and urine culture were included.

Results. Six positive urine cultures were identified among 46 dogs fulfilling search criteria. All six positive cultures were found in dogs with body fat percentage of >45%. In dogs with body fat percentage of <45%, there were no positive urine cultures.

Discussion. There was an increased prevalence of asymptomatic bacteriuria in the morbidly obese dogs in this study compared to those that were lean, overweight, or moderately obese. Whether antibiotic therapy is necessary in such cases is still being debated, but because asymptomatic bacteriuria may be associated with ascending infections, uroliths, or other complications, the data reported herein support the screening of obese patients for bacteriuria.

Obesity and recurrent urinary tract infections in premenopausal women: a retrospective study

OBJECTIVES

Studies on the association between obesity and the risk of urinary tract infection (UTI) show inconsistent results. The aim of this study was to determine whether there is any association between obesity and recurrent UTIs (RUTIs) among premenopausal women.

METHODS

A retrospective case-control study was conducted in the outpatient clinics of the internal medicine departments of three hospitals. All consecutive non-pregnant premenopausal women aged 20-55 years, who presented with RUTIs over a 2-year period, were included; these women were compared to randomly selected women from the same outpatient clinics who had no history of RUTI and were age-matched ±5 years. RUTI was defined as a symptomatic UTI that followed the resolution of a previous UTI, or three or more symptomatic episodes over a 12-month period.

RESULTS

Six hundred and ninety-one premenopausal women with UTI were evaluated during the study period. A total 122 of 162 subjects with RUTIs were included in this study and compared to 122 control cases without a history of RUTI. The overall prevalence of RUTIs among the premenopausal women with UTI was 23.4% (162/691). Approximately half of those with RUTIs were obese. The mean age of women with RUTIs was 43.8±9 vs. 40±10 years among the controls (p=0.839). The mean body mass index of women with RUTIs was significantly higher than that of controls: 35±4 vs. 26±3kg/m(2) (p<0.001). Multivariate regression analysis showed that obesity was associated with RUTIs in premenopausal women (odds ratio 4.00, 95% confidence interval 3.2-4.61; p=0.001).

CONCLUSIONS

Obesity was found to be associated with RUTIs in premenopausal women.

Association between body mass index and urinary tract infection in adult patients

Background:

Overweight and obesity have become a global public health over the last decades. Obesity has been suggested to be a risk factor for some infections, but studies often showed controversial findings. Few studies examined the relationship between body mass index (BMI) and urinary tract infection (UTI), showing inconsistent results.

Objectives:

The purpose of this study was to determine the relationship between BMI and UTI in adult patients.

Patients and Methods:

Adult patients (≥ 18 years old) who were referred to clinics or admitted in hospital with diagnosis of UTI were considered for participation in the study. Control group were selected from healthy adult normal population whom underwent medical check-ups at the same hospital and without history of UTI. Data about age, gender, history of diabetes mellitus and BMI were registered for individuals who met inclusion criteria.

Results:

A total of 116 patients with UTI and 156 people as the control group were included in the study. Two groups were matched for age, gender and history of diabetes mellitus. Mean BMI ± SD of patients was 25.2 ± 4.0 kg/m² and the controls was 25.1 ± 3.6 kg/m². There was no significant correlation between BMI and UTI (P = 0.757). Mean BMI ± SD of patients with upper UTI was 25.6 ± 4.1 kg/m² and for lower UTI was 24.9 ± 4.0 kg/m². There was no significant difference between BMI of controls and patients with any type of UTI (P = 0.573).

Conclusions:

Our findings did not found an association between BMI and UTI and does not support obesity as a risk factor for UTI in adult patients.

Obesity, regardless of comorbidity, influences outcomes after colorectal surgery-time to rethink the pay-for-performance metrics?

An elevated body mass index (BMI) is associated with increased morbidity and mortality after colorectal surgery. While coexistent comorbid conditions are captured in some determinations of case-severity, BMI itself is not factored into pay for performance (P4P) initiatives. From the National Surgical Quality Improvement Program database 2006-2011, obese (BMI ≥30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) patients with and without comorbidity undergoing colorectal resection were identified. Pre- and intraoperative factors as well as postoperative outcomes were compared. Of 130,415 patients, 31.3 % were obese. 80.4 % of obese and 72.9 % of nonobese patients had comorbid conditions. Among obese patients, overall rates of surgical site infection (SSI), wound dehiscence, and various medical complications were significantly higher for those with comorbidity compared to those without (p < 0.001 for all). Obese patients with comorbidity overall had greater risk of renal failure and urinary tract infection than nonobese patients. Regardless of comorbidity, obese patients more commonly had pulmonary embolism, failure to wean from the ventilator, overall SSI, and wound dehiscence. Comorbid factors associated with obesity influence outcomes; however, obesity itself in their absence is associated with worse outcomes. This supports inclusion of obesity as an independent determinant of case-severity, quality, and reimbursement after colorectal surgery.

Risk characterization for urinary tract infections in subjects with newly diagnosed type 2 diabetes

AIM

To evaluate the risk of urinary tract infections (UTI) in subjects with newly diagnosed type 2 diabetes mellitus (T2DM).

METHODS

Subjects aged ≥18years and diagnosed with T2DM between 1/1/10 and 12/31/10 were identified using the MarketScan® databases, which are representative of the commercially insured US population and those with both Medicare and supplemental coverage. The index date was the first T2DM diagnosis date in 2010 (date randomly selected for those without T2DM). Subjects without T2DM were matched (1:1) by index date, age, gender, urban/rural location, and region. All subjects had continuous enrollment for 12 months before (baseline) and after (follow-up) the index date. UTI diagnosis was defined using ICD-9-CM codes. Measurements of glycemic control and body weight were not available. An adjusted logistic regression model assessed the likelihood of UTI.

RESULTS

A total of 89,790 matched pairs were selected. During follow-up, a UTI diagnosis was more common in subjects with T2DM than without T2DM (9.4% vs. 5.7%; p<0.0001). Recurrence of UTI was also more likely with T2DM (1.6% vs. 0.6%; p<0.0001). In a logistic regression, subjects with T2DM had a greater likelihood of UTI during follow up (adjusted odds ratio [OR]=1.54 [95% CI: 1.47-1.60]). This relationship remained after stratifying by gender.

CONCLUSION

Subjects with T2DM were more likely to experience a UTI and recurrent UTIs than subjects without T2DM during follow-up.

Diet modification and metformin have a beneficial effect in a fly model of obesity and mucormycosis

In an experimental model of obesity and hyperglycemia in Drosophila melanogaster we studied the effect of diet modification and administration of metformin on systemic infection with Rhizopus, a common cause of mucormycosis in diabetic patients. Female Wt-type Drosophila flies were fed regular (RF) or high-fat diet (HFD; 30% coconut oil) food with or without metformin for 48 h and then injected with R. oryzae. Survival rates, glucose and triglyceride levels were compared between 1) normal-weight flies (RF), 2) obese flies (HFD), 3) obese flies fed with RF, 4) flies continuously fed on HFD + metformin, 5) flies fed on HFD + metformin, then transferred to RF, and 6) obese flies administered metformin after infection [corrected].Glucose levels were compared across groups of non-infected flies and across groups of infected flies. Survival was significantly decreased (P = 0.003) in obese flies, while post-infection glucose levels were significantly increased (P = 0.0001), compared to normal-weight flies. Diet and administration of metformin led to weight loss, normalized glucose levels during infection, and were associated with decreased mortality and tissue fungal burden. In conclusion, diet and metformin help control infection-associated hyperglycemia and improve survival in Drosophila flies with mucormycosis. Fly models of obesity bear intriguing similarities to the pathophysiology of insulin resistance and diabetes in humans, and can provide new insights into the pathogenesis and treatment of infections in obese and diabetic patients.

Obesity and iron deficiency anemia as risk factors for asymptomatic bacteriuria

BACKGROUND

Few studies examined the risk factors of asymptomatic bacteriuria, showing contradictory results. Our study aimed to examine the association between different clinical and laboratory parameters and asymptomatic bacteriuria in internal medicine patients.

MATERIALS AND METHODS

330 consecutive hospitalized subjects, asymptomatic for urinary tract infections (UTIs), underwent to microscopic examination of urine specimens. 100 subjects were positive for microscopic bacteriuria and were recruited into the study. At the quantitative urine culture 31 subjects of study population were positive while 69 subjects were negative for bacteriuria.

RESULTS

The analysis of clinical characteristics showed that the two groups of subjects (positive and negative urine culture for bacteriuria) were significant different (p<0.05) about obesity (76.7% vs 42% respectively), metabolic syndrome (80.6% vs 44,9%), cholelithiasis (35.5% vs 13,2%) and iron deficiency anemia (80.6% vs 53,6%). The univariate analysis showed that only obesity, cholelithiasis and iron deficiency anemia were positively associated with positive urine culture for bacteriuria (Odds Ratios [OR]=3.79, p=0.0003; OR=2,65, p=0.0091; OR=2.63, p=0.0097; respectively). However, the multivariate analysis by logistic regression showed that only obesity and iron deficiency anemia, independently associated with positive urine culture for bacteriuria (OR=3.9695, p=0.0075; OR=3.1569, p=0.03420 respectively).

CONCLUSIONS

This study shows that obesity and iron deficiency anemia are independent risk factors for asymptomatic bacteriuria.

Urinary tract infection syndromes: occurrence, recurrence, bacteriology, risk factors, and disease burden

Urinary tract infection (UTI) is one of the most common bacterial infections, accounting for 0.9% of all ambulatory visits in the United States. This review defines the major UTI syndromes, their occurrence and recurrence, bacteriology, risk factors, and disease burden.

D-mannose powder for prophylaxis of recurrent urinary tract infections in women: a randomized clinical trial

PURPOSE

To test whether D-mannose powder is effective for recurrent urinary tract infection (UTI) prevention.

MATERIALS AND METHODS

After initial antibiotic treatment of acute cystitis, 308 women with history of recurrent UTI and no other significant comorbidities were randomly allocated to three groups. The first group (n = 103) received prophylaxis with 2 g of D-mannose powder in 200 ml of water daily for 6 months, the second (n = 103) received 50 mg Nitrofurantoin daily, and the third (n = 102) did not receive prophylaxis.

RESULTS

Overall 98 patients (31.8%) had recurrent UTI: 15 (14.6) in the D-mannose group, 21 (20.4) in Nitrofurantoin group, and 62 (60.8) in no prophylaxis group, with the rate significantly higher in no prophylaxis group compared to active groups (P < 0.001). Patients in D-mannose group and Nitrofurantoin group had a significantly lower risk of recurrent UTI episode during prophylactic therapy compared to patients in no prophylaxis group (RR 0.239 and 0.335, P < 0.0001). In active groups, 17.9% of patients reported side effects but they were mild and did not require stopping the prophylaxis. Patients in D-mannose group had a significantly lower risk of side effects compared to patients in Nitrofurantoin group (RR 0.276, P < 0.0001), but the clinical importance of this finding is low because Nitrofurantoin was well tolerated.

CONCLUSIONS

In our study, D-mannose powder had significantly reduced the risk of recurrent UTI which was no different than in Nitrofurantoin group. More studies will be needed to validate the results of this study, but initial findings show that D-mannose may be useful for UTI prevention.