The accelerating burden of cardiometabolic diseases, including hypertension, obesity, and type 2 diabetes mellitus (T2DM), represents one of the most pressing public health challenges of our era. Despite decades of intensive research and the implementation of conventional prevention strategies, improvements in morbidity and mortality have plateaued in many regions, including Japan. Against this backdrop, digital health tools—particularly smartphone applications—have emerged as scalable, patient-centered approaches to bridge gaps in prevention and management. The recently published systematic review and meta-analysis by Abe and colleagues [1] provides a comprehensive and timely synthesis of the evidence, focusing exclusively on smartphone application–based interventions for cardiometabolic risk factor management. This work not only consolidates the state of the science but also highlights important challenges that remain in this field.

Early stage for digital health stemmed from its potential to reach large populations at relatively low cost, harnessing tools already embedded in daily life. With global smartphone penetration exceeding 70% and an estimated 6.1 billion users projected by 2029 [2, 3], the ubiquity of mobile devices offers unprecedented opportunities for behavioral intervention. Smartphone applications can integrate multiple functionalities, including self-monitoring, personalized feedback, educational content, and goal setting. Importantly, they can provide continuous engagement in ways that traditional clinical encounters cannot.

A number of systematic reviews and meta-analyses have previously evaluated digital health interventions more broadly. Widmer et al. [4] demonstrated that such interventions reduce body weight, cholesterol levels, and systolic blood pressure (BP), while Tegegne and colleagues [5] reported favorable effects on multiple cardiometabolic outcomes, including waist circumference and glucose control. However, many earlier studies pooled heterogeneous digital modalities—ranging from short message service (SMS) and email reminders to web-based platforms-making it difficult to parse the specific contribution of smartphone applications.

Focusing more narrowly on mobile applications, Chew et al. [6] confirmed their efficacy in promoting sustained weight loss, while Jahan et al. [7] showed beneficial effects on BMI and body weight among individuals at risk of T2DM. Yet, even these reviews did not fully address long-term outcomes or stratify findings by ethnicity, both of which are essential to tailoring interventions for diverse populations.

Building on this foundation, Abe et al. previously conducted a systematic review of smartphone app–based interventions targeting BP [8]. Their new analysis significantly extends that work, examining a wider range of cardiometabolic risk factors and providing fresh insights into both effectiveness and limitations.

The meta-analysis by Abe and colleagues is remarkable for its breadth, including 76 studies and more than 46,000 participants. Several aspects underscore its novelty; (1) By restricting inclusion to app-based interventions, the study eliminates the confounding influence of other digital tools and offers a cleaner understanding of smartphone-specific effects. (2) Outcomes evaluated extend beyond BP to fasting plasma glucose (FPG), HbA1c, body mass index (BMI), waist circumference, lipid profiles, and quality of life (QOL). This multidimensional perspective is critical, as cardiometabolic risks are tightly interlinked. (3) The investigators assessed effects across follow-up intervals, enabling important observations about the durability of benefit. At 6 months, smartphone applications were associated with significant reductions in FPG ( − 5.65 mg/dL), BMI ( − 0.58 kg/m²), waist circumference ( − 3.37 cm), body weight ( − 1.60 kg), low-density lipoprotein (LDL) cholesterol ( − 7.63 mg/dL), total cholesterol ( − 9.01 mg/dL), and triglycerides ( − 4.69 mg/dL). These effects, however, largely attenuated by 12 months. (4) A novel finding is that LDL cholesterol reductions were greater among East Asian participants compared with non-East Asian groups, raising intriguing questions about genetic, dietary, and environmental interactions. (5) Although no single functionality was consistently associated with improved outcomes, the review highlights that communication platforms, wearable device integration, and regular online or telephone consultations were commonly present in more effective interventions [1]. Collectively, these findings provide robust evidence that smartphone applications can play a meaningful role in cardiometabolic risk reduction—particularly in the short term.

The reductions in cardiometabolic risk factors observed at six months are not only statistically significant but also clinically relevant. For example, lowering FPG by 5.65 mg/dL may translate into a 5–7% reduction in microvascular complications among patients with T2DM [1]. A 3.37 cm decrease in waist circumference is estimated to reduce cardiovascular event risk by approximately 6.5%, while modest improvements in LDL cholesterol and total cholesterol may lower cardiovascular risk by 4–5% [1]. When scaled across populations, these effects could meaningfully impact morbidity and mortality. Importantly, smartphone-based strategies offer the potential to empower patients in self-management, bridging the gap between clinical encounters. They align well with contemporary models of chronic care that emphasize patient engagement, personalization, and integration of technology into everyday life.

Despite these encouraging findings, several challenges remain before smartphone applications can realize their full potential as mainstream tools for cardiometabolic health. (1) The attenuation of benefit by 12 months is a sobering reminder of the perennial challenge of maintaining behavior change. Declining engagement with applications (apps) is well-documented; users often lose motivation once the novelty wears off. Both micro-engagement (daily app use, data entry) and macro-engagement (sustained lifestyle change) must be addressed to prolong benefits. (2) While this review was unable to pinpoint specific functionalities that consistently drive outcomes, prior evidence suggests that goal-setting, personalized feedback, and social support may enhance adherence [9]. Comparative studies that isolate and test individual features are needed. (3) Although smartphone ownership is widespread, digital literacy varies substantially, particularly among older adults and socioeconomically disadvantaged populations. Future interventions must account for these disparities to avoid widening health inequities. (4) Most trials to date have evaluated apps as stand-alone interventions. For maximal impact, they must be embedded into clinical pathways—allowing providers to monitor data, adjust treatment, and deliver timely feedback. Models such as digital therapeutics for hypertension in Japan [10] provide encouraging precedents. (5) Most current evidence focuses on intermediate risk markers. To fully establish clinical utility, future trials should assess hard outcomes such as cardiovascular events, hospitalizations, and mortality. (6) Data security remains a concern, with risks of breaches and unauthorized sharing. As app development increasingly involves commercial entities, clear regulatory frameworks and validation standards will be essential to ensure patient trust.

The study by Abe and colleagues provides a roadmap for where the field should go next. Several priorities stand out: (1) Enhancing engagement, such as gamification, nudging strategies, and AI-driven personalization could sustain user interest and adherence over the long term. (2) Co-creation and usability by involving patients and clinicians in app design can improve usability, reduce burden, and foster sustained engagement. (3) Cultural tailoring by understanding ethnic and cultural differences in app effectiveness—such as the stronger LDL reduction seen in East Asians—can guide the development of targeted interventions. (4) Clinical integration by embedding apps into healthcare delivery systems will maximize their value. For example, linking apps to electronic health records or integrating them into hypertension and diabetes clinics could enable more holistic care. (5) Rigorous evaluation such as large, long-term randomized controlled trials, is needed to test impacts on cardiovascular morbidity and mortality, as well as cost-effectiveness analyses to guide policy decisions.

In conclusion, the systematic review and meta-analysis by Abe and colleagues [1] convincingly demonstrates that smartphone applications can improve multiple cardiometabolic risk factors, particularly over the short term. However, the waning of effects by 12 months and the uncertainty surrounding the most effective app features highlight the need for further innovation. As digital health continues to evolve, smartphone applications should be viewed as valuable adjuncts—rather than replacements—for traditional medical care. Ultimately, the promise of these tools lies not only in their capacity to deliver incremental improvements in risk factors but also in their ability to reshape the patient–provider relationship, empower individuals to take ownership of their health, and enable a more integrated, patient-centered model of care. With thoughtful development, rigorous evaluation, and equitable implementation, smartphone applications may yet become indispensable allies in the fight against the global cardiometabolic epidemic.